First public commit

74 files changed, 17549 insertions, 0 deletions

diff --git a/vendor/github.com/go-kit/kit/LICENSE b/vendor/github.com/go-kit/kit/LICENSE
new file mode 100644
index 0000000..9d83342
--- /dev/null
+++ b/vendor/github.com/go-kit/kit/LICENSE
@@ -0,0 +1,22 @@
+The MIT License (MIT)
+
+Copyright (c) 2015 Peter Bourgon
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
diff --git a/vendor/github.com/go-kit/kit/log/README.md b/vendor/github.com/go-kit/kit/log/README.md
new file mode 100644
index 0000000..7222f80
--- /dev/null
+++ b/vendor/github.com/go-kit/kit/log/README.md
@@ -0,0 +1,147 @@
+# package log
+
+`package log` provides a minimal interface for structured logging in services.
+It may be wrapped to encode conventions, enforce type-safety, provide leveled
+logging, and so on. It can be used for both typical application log events,
+and log-structured data streams.
+
+## Structured logging
+
+Structured logging is, basically, conceding to the reality that logs are
+_data_, and warrant some level of schematic rigor. Using a stricter,
+key/value-oriented message format for our logs, containing contextual and
+semantic information, makes it much easier to get insight into the
+operational activity of the systems we build. Consequently, `package log` is
+of the strong belief that "[the benefits of structured logging outweigh the
+minimal effort involved](https://www.thoughtworks.com/radar/techniques/structured-logging)".
+
+Migrating from unstructured to structured logging is probably a lot easier
+than you'd expect.
+
+```go
+// Unstructured
+log.Printf("HTTP server listening on %s", addr)
+
+// Structured
+logger.Log("transport", "HTTP", "addr", addr, "msg", "listening")
+```
+
+## Usage
+
+### Typical application logging
+
+```go
+w := log.NewSyncWriter(os.Stderr)
+logger := log.NewLogfmtLogger(w)
+logger.Log("question", "what is the meaning of life?", "answer", 42)
+
+// Output:
+// question="what is the meaning of life?" answer=42
+```
+
+### Contextual Loggers
+
+```go
+func main() {
+	var logger log.Logger
+	logger = log.NewLogfmtLogger(log.NewSyncWriter(os.Stderr))
+	logger = log.With(logger, "instance_id", 123)
+
+	logger.Log("msg", "starting")
+	NewWorker(log.With(logger, "component", "worker")).Run()
+	NewSlacker(log.With(logger, "component", "slacker")).Run()
+}
+
+// Output:
+// instance_id=123 msg=starting
+// instance_id=123 component=worker msg=running
+// instance_id=123 component=slacker msg=running
+```
+
+### Interact with stdlib logger
+
+Redirect stdlib logger to Go kit logger.
+
+```go
+import (
+	"os"
+	stdlog "log"
+	kitlog "github.com/go-kit/kit/log"
+)
+
+func main() {
+	logger := kitlog.NewJSONLogger(kitlog.NewSyncWriter(os.Stdout))
+	stdlog.SetOutput(kitlog.NewStdlibAdapter(logger))
+	stdlog.Print("I sure like pie")
+}
+
+// Output:
+// {"msg":"I sure like pie","ts":"2016/01/01 12:34:56"}
+```
+
+Or, if, for legacy reasons, you need to pipe all of your logging through the
+stdlib log package, you can redirect Go kit logger to the stdlib logger.
+
+```go
+logger := kitlog.NewLogfmtLogger(kitlog.StdlibWriter{})
+logger.Log("legacy", true, "msg", "at least it's something")
+
+// Output:
+// 2016/01/01 12:34:56 legacy=true msg="at least it's something"
+```
+
+### Timestamps and callers
+
+```go
+var logger log.Logger
+logger = log.NewLogfmtLogger(log.NewSyncWriter(os.Stderr))
+logger = log.With(logger, "ts", log.DefaultTimestampUTC, "caller", log.DefaultCaller)
+
+logger.Log("msg", "hello")
+
+// Output:
+// ts=2016-01-01T12:34:56Z caller=main.go:15 msg=hello
+```
+
+## Supported output formats
+
+- [Logfmt](https://brandur.org/logfmt) ([see also](https://blog.codeship.com/logfmt-a-log-format-thats-easy-to-read-and-write))
+- JSON
+
+## Enhancements
+
+`package log` is centered on the one-method Logger interface.
+
+```go
+type Logger interface {
+	Log(keyvals ...interface{}) error
+}
+```
+
+This interface, and its supporting code like is the product of much iteration
+and evaluation. For more details on the evolution of the Logger interface,
+see [The Hunt for a Logger Interface](http://go-talks.appspot.com/github.com/ChrisHines/talks/structured-logging/structured-logging.slide#1),
+a talk by [Chris Hines](https://github.com/ChrisHines).
+Also, please see
+[#63](https://github.com/go-kit/kit/issues/63),
+[#76](https://github.com/go-kit/kit/pull/76),
+[#131](https://github.com/go-kit/kit/issues/131),
+[#157](https://github.com/go-kit/kit/pull/157),
+[#164](https://github.com/go-kit/kit/issues/164), and
+[#252](https://github.com/go-kit/kit/pull/252)
+to review historical conversations about package log and the Logger interface.
+
+Value-add packages and suggestions,
+like improvements to [the leveled logger](https://godoc.org/github.com/go-kit/kit/log/level),
+are of course welcome. Good proposals should
+
+- Be composable with [contextual loggers](https://godoc.org/github.com/go-kit/kit/log#With),
+- Not break the behavior of [log.Caller](https://godoc.org/github.com/go-kit/kit/log#Caller) in any wrapped contextual loggers, and
+- Be friendly to packages that accept only an unadorned log.Logger.
+
+## Benchmarks & comparisons
+
+There are a few Go logging benchmarks and comparisons that include Go kit's package log.
+
+- [imkira/go-loggers-bench](https://github.com/imkira/go-loggers-bench) includes kit/log
+- [uber-common/zap](https://github.com/uber-common/zap), a zero-alloc logging library, includes a comparison with kit/log
diff --git a/vendor/github.com/go-kit/kit/log/doc.go b/vendor/github.com/go-kit/kit/log/doc.go
new file mode 100644
index 0000000..918c0af
--- /dev/null
+++ b/vendor/github.com/go-kit/kit/log/doc.go
@@ -0,0 +1,116 @@
+// Package log provides a structured logger.
+//
+// Structured logging produces logs easily consumed later by humans or
+// machines. Humans might be interested in debugging errors, or tracing
+// specific requests. Machines might be interested in counting interesting
+// events, or aggregating information for off-line processing. In both cases,
+// it is important that the log messages are structured and actionable.
+// Package log is designed to encourage both of these best practices.
+//
+// Basic Usage
+//
+// The fundamental interface is Logger. Loggers create log events from
+// key/value data. The Logger interface has a single method, Log, which
+// accepts a sequence of alternating key/value pairs, which this package names
+// keyvals.
+//
+//    type Logger interface {
+//        Log(keyvals ...interface{}) error
+//    }
+//
+// Here is an example of a function using a Logger to create log events.
+//
+//    func RunTask(task Task, logger log.Logger) string {
+//        logger.Log("taskID", task.ID, "event", "starting task")
+//        ...
+//        logger.Log("taskID", task.ID, "event", "task complete")
+//    }
+//
+// The keys in the above example are "taskID" and "event". The values are
+// task.ID, "starting task", and "task complete". Every key is followed
+// immediately by its value.
+//
+// Keys are usually plain strings. Values may be any type that has a sensible
+// encoding in the chosen log format. With structured logging it is a good
+// idea to log simple values without formatting them. This practice allows
+// the chosen logger to encode values in the most appropriate way.
+//
+// Contextual Loggers
+//
+// A contextual logger stores keyvals that it includes in all log events.
+// Building appropriate contextual loggers reduces repetition and aids
+// consistency in the resulting log output. With and WithPrefix add context to
+// a logger. We can use With to improve the RunTask example.
+//
+//    func RunTask(task Task, logger log.Logger) string {
+//        logger = log.With(logger, "taskID", task.ID)
+//        logger.Log("event", "starting task")
+//        ...
+//        taskHelper(task.Cmd, logger)
+//        ...
+//        logger.Log("event", "task complete")
+//    }
+//
+// The improved version emits the same log events as the original for the
+// first and last calls to Log. Passing the contextual logger to taskHelper
+// enables each log event created by taskHelper to include the task.ID even
+// though taskHelper does not have access to that value. Using contextual
+// loggers this way simplifies producing log output that enables tracing the
+// life cycle of individual tasks. (See the Contextual example for the full
+// code of the above snippet.)
+//
+// Dynamic Contextual Values
+//
+// A Valuer function stored in a contextual logger generates a new value each
+// time an event is logged. The Valuer example demonstrates how this feature
+// works.
+//
+// Valuers provide the basis for consistently logging timestamps and source
+// code location. The log package defines several valuers for that purpose.
+// See Timestamp, DefaultTimestamp, DefaultTimestampUTC, Caller, and
+// DefaultCaller. A common logger initialization sequence that ensures all log
+// entries contain a timestamp and source location looks like this:
+//
+//    logger := log.NewLogfmtLogger(log.NewSyncWriter(os.Stdout))
+//    logger = log.With(logger, "ts", log.DefaultTimestampUTC, "caller", log.DefaultCaller)
+//
+// Concurrent Safety
+//
+// Applications with multiple goroutines want each log event written to the
+// same logger to remain separate from other log events. Package log provides
+// two simple solutions for concurrent safe logging.
+//
+// NewSyncWriter wraps an io.Writer and serializes each call to its Write
+// method. Using a SyncWriter has the benefit that the smallest practical
+// portion of the logging logic is performed within a mutex, but it requires
+// the formatting Logger to make only one call to Write per log event.
+//
+// NewSyncLogger wraps any Logger and serializes each call to its Log method.
+// Using a SyncLogger has the benefit that it guarantees each log event is
+// handled atomically within the wrapped logger, but it typically serializes
+// both the formatting and output logic. Use a SyncLogger if the formatting
+// logger may perform multiple writes per log event.
+//
+// Error Handling
+//
+// This package relies on the practice of wrapping or decorating loggers with
+// other loggers to provide composable pieces of functionality. It also means
+// that Logger.Log must return an error because some
+// implementations—especially those that output log data to an io.Writer—may
+// encounter errors that cannot be handled locally. This in turn means that
+// Loggers that wrap other loggers should return errors from the wrapped
+// logger up the stack.
+//
+// Fortunately, the decorator pattern also provides a way to avoid the
+// necessity to check for errors every time an application calls Logger.Log.
+// An application required to panic whenever its Logger encounters
+// an error could initialize its logger as follows.
+//
+//    fmtlogger := log.NewLogfmtLogger(log.NewSyncWriter(os.Stdout))
+//    logger := log.LoggerFunc(func(keyvals ...interface{}) error {
+//        if err := fmtlogger.Log(keyvals...); err != nil {
+//            panic(err)
+//        }
+//        return nil
+//    })
+package log
diff --git a/vendor/github.com/go-kit/kit/log/json_logger.go b/vendor/github.com/go-kit/kit/log/json_logger.go
new file mode 100644
index 0000000..66094b4
--- /dev/null
+++ b/vendor/github.com/go-kit/kit/log/json_logger.go
@@ -0,0 +1,89 @@
+package log
+
+import (
+	"encoding"
+	"encoding/json"
+	"fmt"
+	"io"
+	"reflect"
+)
+
+type jsonLogger struct {
+	io.Writer
+}
+
+// NewJSONLogger returns a Logger that encodes keyvals to the Writer as a
+// single JSON object. Each log event produces no more than one call to
+// w.Write. The passed Writer must be safe for concurrent use by multiple
+// goroutines if the returned Logger will be used concurrently.
+func NewJSONLogger(w io.Writer) Logger {
+	return &jsonLogger{w}
+}
+
+func (l *jsonLogger) Log(keyvals ...interface{}) error {
+	n := (len(keyvals) + 1) / 2 // +1 to handle case when len is odd
+	m := make(map[string]interface{}, n)
+	for i := 0; i < len(keyvals); i += 2 {
+		k := keyvals[i]
+		var v interface{} = ErrMissingValue
+		if i+1 < len(keyvals) {
+			v = keyvals[i+1]
+		}
+		merge(m, k, v)
+	}
+	return json.NewEncoder(l.Writer).Encode(m)
+}
+
+func merge(dst map[string]interface{}, k, v interface{}) {
+	var key string
+	switch x := k.(type) {
+	case string:
+		key = x
+	case fmt.Stringer:
+		key = safeString(x)
+	default:
+		key = fmt.Sprint(x)
+	}
+
+	// We want json.Marshaler and encoding.TextMarshaller to take priority over
+	// err.Error() and v.String(). But json.Marshall (called later) does that by
+	// default so we force a no-op if it's one of those 2 case.
+	switch x := v.(type) {
+	case json.Marshaler:
+	case encoding.TextMarshaler:
+	case error:
+		v = safeError(x)
+	case fmt.Stringer:
+		v = safeString(x)
+	}
+
+	dst[key] = v
+}
+
+func safeString(str fmt.Stringer) (s string) {
+	defer func() {
+		if panicVal := recover(); panicVal != nil {
+			if v := reflect.ValueOf(str); v.Kind() == reflect.Ptr && v.IsNil() {
+				s = "NULL"
+			} else {
+				panic(panicVal)
+			}
+		}
+	}()
+	s = str.String()
+	return
+}
+
+func safeError(err error) (s interface{}) {
+	defer func() {
+		if panicVal := recover(); panicVal != nil {
+			if v := reflect.ValueOf(err); v.Kind() == reflect.Ptr && v.IsNil() {
+				s = nil
+			} else {
+				panic(panicVal)
+			}
+		}
+	}()
+	s = err.Error()
+	return
+}
diff --git a/vendor/github.com/go-kit/kit/log/level/doc.go b/vendor/github.com/go-kit/kit/log/level/doc.go
new file mode 100644
index 0000000..feadc4c
--- /dev/null
+++ b/vendor/github.com/go-kit/kit/log/level/doc.go
@@ -0,0 +1,22 @@
+// Package level implements leveled logging on top of package log. To use the
+// level package, create a logger as per normal in your func main, and wrap it
+// with level.NewFilter.
+//
+//    var logger log.Logger
+//    logger = log.NewLogfmtLogger(os.Stderr)
+//    logger = level.NewFilter(logger, level.AllowInfo()) // <--
+//    logger = log.With(logger, "ts", log.DefaultTimestampUTC)
+//
+// Then, at the callsites, use one of the level.Debug, Info, Warn, or Error
+// helper methods to emit leveled log events.
+//
+//    logger.Log("foo", "bar") // as normal, no level
+//    level.Debug(logger).Log("request_id", reqID, "trace_data", trace.Get())
+//    if value > 100 {
+//        level.Error(logger).Log("value", value)
+//    }
+//
+// NewFilter allows precise control over what happens when a log event is
+// emitted without a level key, or if a squelched level is used. Check the
+// Option functions for details.
+package level
diff --git a/vendor/github.com/go-kit/kit/log/level/level.go b/vendor/github.com/go-kit/kit/log/level/level.go
new file mode 100644
index 0000000..dd4ef60
--- /dev/null
+++ b/vendor/github.com/go-kit/kit/log/level/level.go
@@ -0,0 +1,205 @@
+package level
+
+import "github.com/go-kit/kit/log"
+
+// Error returns a logger that includes a Key/ErrorValue pair.
+func Error(logger log.Logger) log.Logger {
+	return log.WithPrefix(logger, Key(), ErrorValue())
+}
+
+// Warn returns a logger that includes a Key/WarnValue pair.
+func Warn(logger log.Logger) log.Logger {
+	return log.WithPrefix(logger, Key(), WarnValue())
+}
+
+// Info returns a logger that includes a Key/InfoValue pair.
+func Info(logger log.Logger) log.Logger {
+	return log.WithPrefix(logger, Key(), InfoValue())
+}
+
+// Debug returns a logger that includes a Key/DebugValue pair.
+func Debug(logger log.Logger) log.Logger {
+	return log.WithPrefix(logger, Key(), DebugValue())
+}
+
+// NewFilter wraps next and implements level filtering. See the commentary on
+// the Option functions for a detailed description of how to configure levels.
+// If no options are provided, all leveled log events created with Debug,
+// Info, Warn or Error helper methods are squelched and non-leveled log
+// events are passed to next unmodified.
+func NewFilter(next log.Logger, options ...Option) log.Logger {
+	l := &logger{
+		next: next,
+	}
+	for _, option := range options {
+		option(l)
+	}
+	return l
+}
+
+type logger struct {
+	next           log.Logger
+	allowed        level
+	squelchNoLevel bool
+	errNotAllowed  error
+	errNoLevel     error
+}
+
+func (l *logger) Log(keyvals ...interface{}) error {
+	var hasLevel, levelAllowed bool
+	for i := 1; i < len(keyvals); i += 2 {
+		if v, ok := keyvals[i].(*levelValue); ok {
+			hasLevel = true
+			levelAllowed = l.allowed&v.level != 0
+			break
+		}
+	}
+	if !hasLevel && l.squelchNoLevel {
+		return l.errNoLevel
+	}
+	if hasLevel && !levelAllowed {
+		return l.errNotAllowed
+	}
+	return l.next.Log(keyvals...)
+}
+
+// Option sets a parameter for the leveled logger.
+type Option func(*logger)
+
+// AllowAll is an alias for AllowDebug.
+func AllowAll() Option {
+	return AllowDebug()
+}
+
+// AllowDebug allows error, warn, info and debug level log events to pass.
+func AllowDebug() Option {
+	return allowed(levelError | levelWarn | levelInfo | levelDebug)
+}
+
+// AllowInfo allows error, warn and info level log events to pass.
+func AllowInfo() Option {
+	return allowed(levelError | levelWarn | levelInfo)
+}
+
+// AllowWarn allows error and warn level log events to pass.
+func AllowWarn() Option {
+	return allowed(levelError | levelWarn)
+}
+
+// AllowError allows only error level log events to pass.
+func AllowError() Option {
+	return allowed(levelError)
+}
+
+// AllowNone allows no leveled log events to pass.
+func AllowNone() Option {
+	return allowed(0)
+}
+
+func allowed(allowed level) Option {
+	return func(l *logger) { l.allowed = allowed }
+}
+
+// ErrNotAllowed sets the error to return from Log when it squelches a log
+// event disallowed by the configured Allow[Level] option. By default,
+// ErrNotAllowed is nil; in this case the log event is squelched with no
+// error.
+func ErrNotAllowed(err error) Option {
+	return func(l *logger) { l.errNotAllowed = err }
+}
+
+// SquelchNoLevel instructs Log to squelch log events with no level, so that
+// they don't proceed through to the wrapped logger. If SquelchNoLevel is set
+// to true and a log event is squelched in this way, the error value
+// configured with ErrNoLevel is returned to the caller.
+func SquelchNoLevel(squelch bool) Option {
+	return func(l *logger) { l.squelchNoLevel = squelch }
+}
+
+// ErrNoLevel sets the error to return from Log when it squelches a log event
+// with no level. By default, ErrNoLevel is nil; in this case the log event is
+// squelched with no error.
+func ErrNoLevel(err error) Option {
+	return func(l *logger) { l.errNoLevel = err }
+}
+
+// NewInjector wraps next and returns a logger that adds a Key/level pair to
+// the beginning of log events that don't already contain a level. In effect,
+// this gives a default level to logs without a level.
+func NewInjector(next log.Logger, level Value) log.Logger {
+	return &injector{
+		next:  next,
+		level: level,
+	}
+}
+
+type injector struct {
+	next  log.Logger
+	level interface{}
+}
+
+func (l *injector) Log(keyvals ...interface{}) error {
+	for i := 1; i < len(keyvals); i += 2 {
+		if _, ok := keyvals[i].(*levelValue); ok {
+			return l.next.Log(keyvals...)
+		}
+	}
+	kvs := make([]interface{}, len(keyvals)+2)
+	kvs[0], kvs[1] = key, l.level
+	copy(kvs[2:], keyvals)
+	return l.next.Log(kvs...)
+}
+
+// Value is the interface that each of the canonical level values implement.
+// It contains unexported methods that prevent types from other packages from
+// implementing it and guaranteeing that NewFilter can distinguish the levels
+// defined in this package from all other values.
+type Value interface {
+	String() string
+	levelVal()
+}
+
+// Key returns the unique key added to log events by the loggers in this
+// package.
+func Key() interface{} { return key }
+
+// ErrorValue returns the unique value added to log events by Error.
+func ErrorValue() Value { return errorValue }
+
+// WarnValue returns the unique value added to log events by Warn.
+func WarnValue() Value { return warnValue }
+
+// InfoValue returns the unique value added to log events by Info.
+func InfoValue() Value { return infoValue }
+
+// DebugValue returns the unique value added to log events by Warn.
+func DebugValue() Value { return debugValue }
+
+var (
+	// key is of type interfae{} so that it allocates once during package
+	// initialization and avoids allocating every time the value is added to a
+	// []interface{} later.
+	key interface{} = "level"
+
+	errorValue = &levelValue{level: levelError, name: "error"}
+	warnValue  = &levelValue{level: levelWarn, name: "warn"}
+	infoValue  = &levelValue{level: levelInfo, name: "info"}
+	debugValue = &levelValue{level: levelDebug, name: "debug"}
+)
+
+type level byte
+
+const (
+	levelDebug level = 1 << iota
+	levelInfo
+	levelWarn
+	levelError
+)
+
+type levelValue struct {
+	name string
+	level
+}
+
+func (v *levelValue) String() string { return v.name }
+func (v *levelValue) levelVal()      {}
diff --git a/vendor/github.com/go-kit/kit/log/log.go b/vendor/github.com/go-kit/kit/log/log.go
new file mode 100644
index 0000000..66a9e2f
--- /dev/null
+++ b/vendor/github.com/go-kit/kit/log/log.go
@@ -0,0 +1,135 @@
+package log
+
+import "errors"
+
+// Logger is the fundamental interface for all log operations. Log creates a
+// log event from keyvals, a variadic sequence of alternating keys and values.
+// Implementations must be safe for concurrent use by multiple goroutines. In
+// particular, any implementation of Logger that appends to keyvals or
+// modifies or retains any of its elements must make a copy first.
+type Logger interface {
+	Log(keyvals ...interface{}) error
+}
+
+// ErrMissingValue is appended to keyvals slices with odd length to substitute
+// the missing value.
+var ErrMissingValue = errors.New("(MISSING)")
+
+// With returns a new contextual logger with keyvals prepended to those passed
+// to calls to Log. If logger is also a contextual logger created by With or
+// WithPrefix, keyvals is appended to the existing context.
+//
+// The returned Logger replaces all value elements (odd indexes) containing a
+// Valuer with their generated value for each call to its Log method.
+func With(logger Logger, keyvals ...interface{}) Logger {
+	if len(keyvals) == 0 {
+		return logger
+	}
+	l := newContext(logger)
+	kvs := append(l.keyvals, keyvals...)
+	if len(kvs)%2 != 0 {
+		kvs = append(kvs, ErrMissingValue)
+	}
+	return &context{
+		logger: l.logger,
+		// Limiting the capacity of the stored keyvals ensures that a new
+		// backing array is created if the slice must grow in Log or With.
+		// Using the extra capacity without copying risks a data race that
+		// would violate the Logger interface contract.
+		keyvals:   kvs[:len(kvs):len(kvs)],
+		hasValuer: l.hasValuer || containsValuer(keyvals),
+	}
+}
+
+// WithPrefix returns a new contextual logger with keyvals prepended to those
+// passed to calls to Log. If logger is also a contextual logger created by
+// With or WithPrefix, keyvals is prepended to the existing context.
+//
+// The returned Logger replaces all value elements (odd indexes) containing a
+// Valuer with their generated value for each call to its Log method.
+func WithPrefix(logger Logger, keyvals ...interface{}) Logger {
+	if len(keyvals) == 0 {
+		return logger
+	}
+	l := newContext(logger)
+	// Limiting the capacity of the stored keyvals ensures that a new
+	// backing array is created if the slice must grow in Log or With.
+	// Using the extra capacity without copying risks a data race that
+	// would violate the Logger interface contract.
+	n := len(l.keyvals) + len(keyvals)
+	if len(keyvals)%2 != 0 {
+		n++
+	}
+	kvs := make([]interface{}, 0, n)
+	kvs = append(kvs, keyvals...)
+	if len(kvs)%2 != 0 {
+		kvs = append(kvs, ErrMissingValue)
+	}
+	kvs = append(kvs, l.keyvals...)
+	return &context{
+		logger:    l.logger,
+		keyvals:   kvs,
+		hasValuer: l.hasValuer || containsValuer(keyvals),
+	}
+}
+
+// context is the Logger implementation returned by With and WithPrefix. It
+// wraps a Logger and holds keyvals that it includes in all log events. Its
+// Log method calls bindValues to generate values for each Valuer in the
+// context keyvals.
+//
+// A context must always have the same number of stack frames between calls to
+// its Log method and the eventual binding of Valuers to their value. This
+// requirement comes from the functional requirement to allow a context to
+// resolve application call site information for a Caller stored in the
+// context. To do this we must be able to predict the number of logging
+// functions on the stack when bindValues is called.
+//
+// Two implementation details provide the needed stack depth consistency.
+//
+//    1. newContext avoids introducing an additional layer when asked to
+//       wrap another context.
+//    2. With and WithPrefix avoid introducing an additional layer by
+//       returning a newly constructed context with a merged keyvals rather
+//       than simply wrapping the existing context.
+type context struct {
+	logger    Logger
+	keyvals   []interface{}
+	hasValuer bool
+}
+
+func newContext(logger Logger) *context {
+	if c, ok := logger.(*context); ok {
+		return c
+	}
+	return &context{logger: logger}
+}
+
+// Log replaces all value elements (odd indexes) containing a Valuer in the
+// stored context with their generated value, appends keyvals, and passes the
+// result to the wrapped Logger.
+func (l *context) Log(keyvals ...interface{}) error {
+	kvs := append(l.keyvals, keyvals...)
+	if len(kvs)%2 != 0 {
+		kvs = append(kvs, ErrMissingValue)
+	}
+	if l.hasValuer {
+		// If no keyvals were appended above then we must copy l.keyvals so
+		// that future log events will reevaluate the stored Valuers.
+		if len(keyvals) == 0 {
+			kvs = append([]interface{}{}, l.keyvals...)
+		}
+		bindValues(kvs[:len(l.keyvals)])
+	}
+	return l.logger.Log(kvs...)
+}
+
+// LoggerFunc is an adapter to allow use of ordinary functions as Loggers. If
+// f is a function with the appropriate signature, LoggerFunc(f) is a Logger
+// object that calls f.
+type LoggerFunc func(...interface{}) error
+
+// Log implements Logger by calling f(keyvals...).
+func (f LoggerFunc) Log(keyvals ...interface{}) error {
+	return f(keyvals...)
+}
diff --git a/vendor/github.com/go-kit/kit/log/logfmt_logger.go b/vendor/github.com/go-kit/kit/log/logfmt_logger.go
new file mode 100644
index 0000000..a003052
--- /dev/null
+++ b/vendor/github.com/go-kit/kit/log/logfmt_logger.go
@@ -0,0 +1,62 @@
+package log
+
+import (
+	"bytes"
+	"io"
+	"sync"
+
+	"github.com/go-logfmt/logfmt"
+)
+
+type logfmtEncoder struct {
+	*logfmt.Encoder
+	buf bytes.Buffer
+}
+
+func (l *logfmtEncoder) Reset() {
+	l.Encoder.Reset()
+	l.buf.Reset()
+}
+
+var logfmtEncoderPool = sync.Pool{
+	New: func() interface{} {
+		var enc logfmtEncoder
+		enc.Encoder = logfmt.NewEncoder(&enc.buf)
+		return &enc
+	},
+}
+
+type logfmtLogger struct {
+	w io.Writer
+}
+
+// NewLogfmtLogger returns a logger that encodes keyvals to the Writer in
+// logfmt format. Each log event produces no more than one call to w.Write.
+// The passed Writer must be safe for concurrent use by multiple goroutines if
+// the returned Logger will be used concurrently.
+func NewLogfmtLogger(w io.Writer) Logger {
+	return &logfmtLogger{w}
+}
+
+func (l logfmtLogger) Log(keyvals ...interface{}) error {
+	enc := logfmtEncoderPool.Get().(*logfmtEncoder)
+	enc.Reset()
+	defer logfmtEncoderPool.Put(enc)
+
+	if err := enc.EncodeKeyvals(keyvals...); err != nil {
+		return err
+	}
+
+	// Add newline to the end of the buffer
+	if err := enc.EndRecord(); err != nil {
+		return err
+	}
+
+	// The Logger interface requires implementations to be safe for concurrent
+	// use by multiple goroutines. For this implementation that means making
+	// only one call to l.w.Write() for each call to Log.
+	if _, err := l.w.Write(enc.buf.Bytes()); err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/vendor/github.com/go-kit/kit/log/nop_logger.go b/vendor/github.com/go-kit/kit/log/nop_logger.go
new file mode 100644
index 0000000..1047d62
--- /dev/null
+++ b/vendor/github.com/go-kit/kit/log/nop_logger.go
@@ -0,0 +1,8 @@
+package log
+
+type nopLogger struct{}
+
+// NewNopLogger returns a logger that doesn't do anything.
+func NewNopLogger() Logger { return nopLogger{} }
+
+func (nopLogger) Log(...interface{}) error { return nil }
diff --git a/vendor/github.com/go-kit/kit/log/stdlib.go b/vendor/github.com/go-kit/kit/log/stdlib.go
new file mode 100644
index 0000000..ff96b5d
--- /dev/null
+++ b/vendor/github.com/go-kit/kit/log/stdlib.go
@@ -0,0 +1,116 @@
+package log
+
+import (
+	"io"
+	"log"
+	"regexp"
+	"strings"
+)
+
+// StdlibWriter implements io.Writer by invoking the stdlib log.Print. It's
+// designed to be passed to a Go kit logger as the writer, for cases where
+// it's necessary to redirect all Go kit log output to the stdlib logger.
+//
+// If you have any choice in the matter, you shouldn't use this. Prefer to
+// redirect the stdlib log to the Go kit logger via NewStdlibAdapter.
+type StdlibWriter struct{}
+
+// Write implements io.Writer.
+func (w StdlibWriter) Write(p []byte) (int, error) {
+	log.Print(strings.TrimSpace(string(p)))
+	return len(p), nil
+}
+
+// StdlibAdapter wraps a Logger and allows it to be passed to the stdlib
+// logger's SetOutput. It will extract date/timestamps, filenames, and
+// messages, and place them under relevant keys.
+type StdlibAdapter struct {
+	Logger
+	timestampKey string
+	fileKey      string
+	messageKey   string
+}
+
+// StdlibAdapterOption sets a parameter for the StdlibAdapter.
+type StdlibAdapterOption func(*StdlibAdapter)
+
+// TimestampKey sets the key for the timestamp field. By default, it's "ts".
+func TimestampKey(key string) StdlibAdapterOption {
+	return func(a *StdlibAdapter) { a.timestampKey = key }
+}
+
+// FileKey sets the key for the file and line field. By default, it's "caller".
+func FileKey(key string) StdlibAdapterOption {
+	return func(a *StdlibAdapter) { a.fileKey = key }
+}
+
+// MessageKey sets the key for the actual log message. By default, it's "msg".
+func MessageKey(key string) StdlibAdapterOption {
+	return func(a *StdlibAdapter) { a.messageKey = key }
+}
+
+// NewStdlibAdapter returns a new StdlibAdapter wrapper around the passed
+// logger. It's designed to be passed to log.SetOutput.
+func NewStdlibAdapter(logger Logger, options ...StdlibAdapterOption) io.Writer {
+	a := StdlibAdapter{
+		Logger:       logger,
+		timestampKey: "ts",
+		fileKey:      "caller",
+		messageKey:   "msg",
+	}
+	for _, option := range options {
+		option(&a)
+	}
+	return a
+}
+
+func (a StdlibAdapter) Write(p []byte) (int, error) {
+	result := subexps(p)
+	keyvals := []interface{}{}
+	var timestamp string
+	if date, ok := result["date"]; ok && date != "" {
+		timestamp = date
+	}
+	if time, ok := result["time"]; ok && time != "" {
+		if timestamp != "" {
+			timestamp += " "
+		}
+		timestamp += time
+	}
+	if timestamp != "" {
+		keyvals = append(keyvals, a.timestampKey, timestamp)
+	}
+	if file, ok := result["file"]; ok && file != "" {
+		keyvals = append(keyvals, a.fileKey, file)
+	}
+	if msg, ok := result["msg"]; ok {
+		keyvals = append(keyvals, a.messageKey, msg)
+	}
+	if err := a.Logger.Log(keyvals...); err != nil {
+		return 0, err
+	}
+	return len(p), nil
+}
+
+const (
+	logRegexpDate = `(?P<date>[0-9]{4}/[0-9]{2}/[0-9]{2})?[ ]?`
+	logRegexpTime = `(?P<time>[0-9]{2}:[0-9]{2}:[0-9]{2}(\.[0-9]+)?)?[ ]?`
+	logRegexpFile = `(?P<file>.+?:[0-9]+)?`
+	logRegexpMsg  = `(: )?(?P<msg>.*)`
+)
+
+var (
+	logRegexp = regexp.MustCompile(logRegexpDate + logRegexpTime + logRegexpFile + logRegexpMsg)
+)
+
+func subexps(line []byte) map[string]string {
+	m := logRegexp.FindSubmatch(line)
+	if len(m) < len(logRegexp.SubexpNames()) {
+		return map[string]string{}
+	}
+	result := map[string]string{}
+	for i, name := range logRegexp.SubexpNames() {
+		result[name] = string(m[i])
+	}
+	return result
+}
diff --git a/vendor/github.com/go-kit/kit/log/sync.go b/vendor/github.com/go-kit/kit/log/sync.go
new file mode 100644
index 0000000..c07cdfa
--- /dev/null
+++ b/vendor/github.com/go-kit/kit/log/sync.go
@@ -0,0 +1,116 @@
+package log
+
+import (
+	"io"
+	"sync"
+	"sync/atomic"
+)
+
+// SwapLogger wraps another logger that may be safely replaced while other
+// goroutines use the SwapLogger concurrently. The zero value for a SwapLogger
+// will discard all log events without error.
+//
+// SwapLogger serves well as a package global logger that can be changed by
+// importers.
+type SwapLogger struct {
+	logger atomic.Value
+}
+
+type loggerStruct struct {
+	Logger
+}
+
+// Log implements the Logger interface by forwarding keyvals to the currently
+// wrapped logger. It does not log anything if the wrapped logger is nil.
+func (l *SwapLogger) Log(keyvals ...interface{}) error {
+	s, ok := l.logger.Load().(loggerStruct)
+	if !ok || s.Logger == nil {
+		return nil
+	}
+	return s.Log(keyvals...)
+}
+
+// Swap replaces the currently wrapped logger with logger. Swap may be called
+// concurrently with calls to Log from other goroutines.
+func (l *SwapLogger) Swap(logger Logger) {
+	l.logger.Store(loggerStruct{logger})
+}
+
+// NewSyncWriter returns a new writer that is safe for concurrent use by
+// multiple goroutines. Writes to the returned writer are passed on to w. If
+// another write is already in progress, the calling goroutine blocks until
+// the writer is available.
+//
+// If w implements the following interface, so does the returned writer.
+//
+//    interface {
+//        Fd() uintptr
+//    }
+func NewSyncWriter(w io.Writer) io.Writer {
+	switch w := w.(type) {
+	case fdWriter:
+		return &fdSyncWriter{fdWriter: w}
+	default:
+		return &syncWriter{Writer: w}
+	}
+}
+
+// syncWriter synchronizes concurrent writes to an io.Writer.
+type syncWriter struct {
+	sync.Mutex
+	io.Writer
+}
+
+// Write writes p to the underlying io.Writer. If another write is already in
+// progress, the calling goroutine blocks until the syncWriter is available.
+func (w *syncWriter) Write(p []byte) (n int, err error) {
+	w.Lock()
+	n, err = w.Writer.Write(p)
+	w.Unlock()
+	return n, err
+}
+
+// fdWriter is an io.Writer that also has an Fd method. The most common
+// example of an fdWriter is an *os.File.
+type fdWriter interface {
+	io.Writer
+	Fd() uintptr
+}
+
+// fdSyncWriter synchronizes concurrent writes to an fdWriter.
+type fdSyncWriter struct {
+	sync.Mutex
+	fdWriter
+}
+
+// Write writes p to the underlying io.Writer. If another write is already in
+// progress, the calling goroutine blocks until the fdSyncWriter is available.
+func (w *fdSyncWriter) Write(p []byte) (n int, err error) {
+	w.Lock()
+	n, err = w.fdWriter.Write(p)
+	w.Unlock()
+	return n, err
+}
+
+// syncLogger provides concurrent safe logging for another Logger.
+type syncLogger struct {
+	mu     sync.Mutex
+	logger Logger
+}
+
+// NewSyncLogger returns a logger that synchronizes concurrent use of the
+// wrapped logger. When multiple goroutines use the SyncLogger concurrently
+// only one goroutine will be allowed to log to the wrapped logger at a time.
+// The other goroutines will block until the logger is available.
+func NewSyncLogger(logger Logger) Logger {
+	return &syncLogger{logger: logger}
+}
+
+// Log logs keyvals to the underlying Logger. If another log is already in
+// progress, the calling goroutine blocks until the syncLogger is available.
+func (l *syncLogger) Log(keyvals ...interface{}) error {
+	l.mu.Lock()
+	err := l.logger.Log(keyvals...)
+	l.mu.Unlock()
+	return err
+}
diff --git a/vendor/github.com/go-kit/kit/log/term/LICENSE b/vendor/github.com/go-kit/kit/log/term/LICENSE
new file mode 100644
index 0000000..f090cb4
--- /dev/null
+++ b/vendor/github.com/go-kit/kit/log/term/LICENSE
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2014 Simon Eskildsen
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/vendor/github.com/go-kit/kit/log/value.go b/vendor/github.com/go-kit/kit/log/value.go
new file mode 100644
index 0000000..b56f154
--- /dev/null
+++ b/vendor/github.com/go-kit/kit/log/value.go
@@ -0,0 +1,102 @@
+package log
+
+import (
+	"time"
+
+	"github.com/go-stack/stack"
+)
+
+// A Valuer generates a log value. When passed to With or WithPrefix in a
+// value element (odd indexes), it represents a dynamic value which is re-
+// evaluated with each log event.
+type Valuer func() interface{}
+
+// bindValues replaces all value elements (odd indexes) containing a Valuer
+// with their generated value.
+func bindValues(keyvals []interface{}) {
+	for i := 1; i < len(keyvals); i += 2 {
+		if v, ok := keyvals[i].(Valuer); ok {
+			keyvals[i] = v()
+		}
+	}
+}
+
+// containsValuer returns true if any of the value elements (odd indexes)
+// contain a Valuer.
+func containsValuer(keyvals []interface{}) bool {
+	for i := 1; i < len(keyvals); i += 2 {
+		if _, ok := keyvals[i].(Valuer); ok {
+			return true
+		}
+	}
+	return false
+}
+
+// Timestamp returns a timestamp Valuer. It invokes the t function to get the
+// time; unless you are doing something tricky, pass time.Now.
+//
+// Most users will want to use DefaultTimestamp or DefaultTimestampUTC, which
+// are TimestampFormats that use the RFC3339Nano format.
+func Timestamp(t func() time.Time) Valuer {
+	return func() interface{} { return t() }
+}
+
+// TimestampFormat returns a timestamp Valuer with a custom time format. It
+// invokes the t function to get the time to format; unless you are doing
+// something tricky, pass time.Now. The layout string is passed to
+// Time.Format.
+//
+// Most users will want to use DefaultTimestamp or DefaultTimestampUTC, which
+// are TimestampFormats that use the RFC3339Nano format.
+func TimestampFormat(t func() time.Time, layout string) Valuer {
+	return func() interface{} {
+		return timeFormat{
+			time:   t(),
+			layout: layout,
+		}
+	}
+}
+
+// A timeFormat represents an instant in time and a layout used when
+// marshaling to a text format.
+type timeFormat struct {
+	time   time.Time
+	layout string
+}
+
+func (tf timeFormat) String() string {
+	return tf.time.Format(tf.layout)
+}
+
+// MarshalText implements encoding.TextMarshaller.
+func (tf timeFormat) MarshalText() (text []byte, err error) {
+	// The following code adapted from the standard library time.Time.Format
+	// method. Using the same undocumented magic constant to extend the size
+	// of the buffer as seen there.
+	b := make([]byte, 0, len(tf.layout)+10)
+	b = tf.time.AppendFormat(b, tf.layout)
+	return b, nil
+}
+
+// Caller returns a Valuer that returns a file and line from a specified depth
+// in the callstack. Users will probably want to use DefaultCaller.
+func Caller(depth int) Valuer {
+	return func() interface{} { return stack.Caller(depth) }
+}
+
+var (
+	// DefaultTimestamp is a Valuer that returns the current wallclock time,
+	// respecting time zones, when bound.
+	DefaultTimestamp = TimestampFormat(time.Now, time.RFC3339Nano)
+
+	// DefaultTimestampUTC is a Valuer that returns the current time in UTC
+	// when bound.
+	DefaultTimestampUTC = TimestampFormat(
+		func() time.Time { return time.Now().UTC() },
+		time.RFC3339Nano,
+	)
+
+	// DefaultCaller is a Valuer that returns the file and line where the Log
+	// method was invoked. It can only be used with log.With.
+	DefaultCaller = Caller(3)
+)
diff --git a/vendor/github.com/go-logfmt/logfmt/.gitignore b/vendor/github.com/go-logfmt/logfmt/.gitignore
new file mode 100644
index 0000000..320e53e
--- /dev/null
+++ b/vendor/github.com/go-logfmt/logfmt/.gitignore
@@ -0,0 +1,4 @@
+_testdata/
+_testdata2/
+logfmt-fuzz.zip
+logfmt.test.exe
diff --git a/vendor/github.com/go-logfmt/logfmt/.travis.yml b/vendor/github.com/go-logfmt/logfmt/.travis.yml
new file mode 100644
index 0000000..b599f65
--- /dev/null
+++ b/vendor/github.com/go-logfmt/logfmt/.travis.yml
@@ -0,0 +1,15 @@
+language: go
+sudo: false
+go:
+  - 1.3
+  - 1.4
+  - 1.5
+  - 1.6
+  - tip
+
+before_install:
+  - go get github.com/mattn/goveralls
+  - go get golang.org/x/tools/cmd/cover
+
+script:
+  - goveralls -service=travis-ci
diff --git a/vendor/github.com/go-logfmt/logfmt/LICENSE b/vendor/github.com/go-logfmt/logfmt/LICENSE
new file mode 100644
index 0000000..c026508
--- /dev/null
+++ b/vendor/github.com/go-logfmt/logfmt/LICENSE
@@ -0,0 +1,22 @@
+The MIT License (MIT)
+
+Copyright (c) 2015 go-logfmt
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
diff --git a/vendor/github.com/go-logfmt/logfmt/README.md b/vendor/github.com/go-logfmt/logfmt/README.md
new file mode 100644
index 0000000..3a8f10b
--- /dev/null
+++ b/vendor/github.com/go-logfmt/logfmt/README.md
@@ -0,0 +1,33 @@
+[![GoDoc](https://godoc.org/github.com/go-logfmt/logfmt?status.svg)](https://godoc.org/github.com/go-logfmt/logfmt)
+[![Go Report Card](https://goreportcard.com/badge/go-logfmt/logfmt)](https://goreportcard.com/report/go-logfmt/logfmt)
+[![TravisCI](https://travis-ci.org/go-logfmt/logfmt.svg?branch=master)](https://travis-ci.org/go-logfmt/logfmt)
+[![Coverage Status](https://coveralls.io/repos/github/go-logfmt/logfmt/badge.svg?branch=master)](https://coveralls.io/github/go-logfmt/logfmt?branch=master)
+
+# logfmt
+
+Package logfmt implements utilities to marshal and unmarshal data in the [logfmt
+format](https://brandur.org/logfmt). It provides an API similar to
+[encoding/json](http://golang.org/pkg/encoding/json/) and
+[encoding/xml](http://golang.org/pkg/encoding/xml/).
+
+The logfmt format was first documented by Brandur Leach in [this
+article](https://brandur.org/logfmt). The format has not been formally
+standardized. The most authoritative public specification to date has been the
+documentation of a Go Language [package](http://godoc.org/github.com/kr/logfmt)
+written by Blake Mizerany and Keith Rarick.
+
+## Goals
+
+This project attempts to conform as closely as possible to the prior art, while
+also removing ambiguity where necessary to provide well behaved encoder and
+decoder implementations.
+
+## Non-goals
+
+This project does not attempt to formally standardize the logfmt format. In the
+event that logfmt is standardized this project would take conforming to the
+standard as a goal.
+
+## Versioning
+
+Package logfmt publishes releases via [semver](http://semver.org/) compatible Git tags prefixed with a single 'v'.
diff --git a/vendor/github.com/go-logfmt/logfmt/decode.go b/vendor/github.com/go-logfmt/logfmt/decode.go
new file mode 100644
index 0000000..04e0eff
--- /dev/null
+++ b/vendor/github.com/go-logfmt/logfmt/decode.go
@@ -0,0 +1,237 @@
+package logfmt
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"unicode/utf8"
+)
+
+// A Decoder reads and decodes logfmt records from an input stream.
+type Decoder struct {
+	pos     int
+	key     []byte
+	value   []byte
+	lineNum int
+	s       *bufio.Scanner
+	err     error
+}
+
+// NewDecoder returns a new decoder that reads from r.
+//
+// The decoder introduces its own buffering and may read data from r beyond
+// the logfmt records requested.
+func NewDecoder(r io.Reader) *Decoder {
+	dec := &Decoder{
+		s: bufio.NewScanner(r),
+	}
+	return dec
+}
+
+// ScanRecord advances the Decoder to the next record, which can then be
+// parsed with the ScanKeyval method. It returns false when decoding stops,
+// either by reaching the end of the input or an error. After ScanRecord
+// returns false, the Err method will return any error that occurred during
+// decoding, except that if it was io.EOF, Err will return nil.
+func (dec *Decoder) ScanRecord() bool {
+	if dec.err != nil {
+		return false
+	}
+	if !dec.s.Scan() {
+		dec.err = dec.s.Err()
+		return false
+	}
+	dec.lineNum++
+	dec.pos = 0
+	return true
+}
+
+// ScanKeyval advances the Decoder to the next key/value pair of the current
+// record, which can then be retrieved with the Key and Value methods. It
+// returns false when decoding stops, either by reaching the end of the
+// current record or an error.
+func (dec *Decoder) ScanKeyval() bool {
+	dec.key, dec.value = nil, nil
+	if dec.err != nil {
+		return false
+	}
+
+	line := dec.s.Bytes()
+
+	// garbage
+	for p, c := range line[dec.pos:] {
+		if c > ' ' {
+			dec.pos += p
+			goto key
+		}
+	}
+	dec.pos = len(line)
+	return false
+
+key:
+	const invalidKeyError = "invalid key"
+
+	start, multibyte := dec.pos, false
+	for p, c := range line[dec.pos:] {
+		switch {
+		case c == '=':
+			dec.pos += p
+			if dec.pos > start {
+				dec.key = line[start:dec.pos]
+				if multibyte && bytes.IndexRune(dec.key, utf8.RuneError) != -1 {
+					dec.syntaxError(invalidKeyError)
+					return false
+				}
+			}
+			if dec.key == nil {
+				dec.unexpectedByte(c)
+				return false
+			}
+			goto equal
+		case c == '"':
+			dec.pos += p
+			dec.unexpectedByte(c)
+			return false
+		case c <= ' ':
+			dec.pos += p
+			if dec.pos > start {
+				dec.key = line[start:dec.pos]
+				if multibyte && bytes.IndexRune(dec.key, utf8.RuneError) != -1 {
+					dec.syntaxError(invalidKeyError)
+					return false
+				}
+			}
+			return true
+		case c >= utf8.RuneSelf:
+			multibyte = true
+		}
+	}
+	dec.pos = len(line)
+	if dec.pos > start {
+		dec.key = line[start:dec.pos]
+		if multibyte && bytes.IndexRune(dec.key, utf8.RuneError) != -1 {
+			dec.syntaxError(invalidKeyError)
+			return false
+		}
+	}
+	return true
+
+equal:
+	dec.pos++
+	if dec.pos >= len(line) {
+		return true
+	}
+	switch c := line[dec.pos]; {
+	case c <= ' ':
+		return true
+	case c == '"':
+		goto qvalue
+	}
+
+	// value
+	start = dec.pos
+	for p, c := range line[dec.pos:] {
+		switch {
+		case c == '=' || c == '"':
+			dec.pos += p
+			dec.unexpectedByte(c)
+			return false
+		case c <= ' ':
+			dec.pos += p
+			if dec.pos > start {
+				dec.value = line[start:dec.pos]
+			}
+			return true
+		}
+	}
+	dec.pos = len(line)
+	if dec.pos > start {
+		dec.value = line[start:dec.pos]
+	}
+	return true
+
+qvalue:
+	const (
+		untermQuote  = "unterminated quoted value"
+		invalidQuote = "invalid quoted value"
+	)
+
+	hasEsc, esc := false, false
+	start = dec.pos
+	for p, c := range line[dec.pos+1:] {
+		switch {
+		case esc:
+			esc = false
+		case c == '\\':
+			hasEsc, esc = true, true
+		case c == '"':
+			dec.pos += p + 2
+			if hasEsc {
+				v, ok := unquoteBytes(line[start:dec.pos])
+				if !ok {
+					dec.syntaxError(invalidQuote)
+					return false
+				}
+				dec.value = v
+			} else {
+				start++
+				end := dec.pos - 1
+				if end > start {
+					dec.value = line[start:end]
+				}
+			}
+			return true
+		}
+	}
+	dec.pos = len(line)
+	dec.syntaxError(untermQuote)
+	return false
+}
+
+// Key returns the most recent key found by a call to ScanKeyval. The returned
+// slice may point to internal buffers and is only valid until the next call
+// to ScanRecord.  It does no allocation.
+func (dec *Decoder) Key() []byte {
+	return dec.key
+}
+
+// Value returns the most recent value found by a call to ScanKeyval. The
+// returned slice may point to internal buffers and is only valid until the
+// next call to ScanRecord.  It does no allocation when the value has no
+// escape sequences.
+func (dec *Decoder) Value() []byte {
+	return dec.value
+}
+
+// Err returns the first non-EOF error that was encountered by the Scanner.
+func (dec *Decoder) Err() error {
+	return dec.err
+}
+
+func (dec *Decoder) syntaxError(msg string) {
+	dec.err = &SyntaxError{
+		Msg:  msg,
+		Line: dec.lineNum,
+		Pos:  dec.pos + 1,
+	}
+}
+
+func (dec *Decoder) unexpectedByte(c byte) {
+	dec.err = &SyntaxError{
+		Msg:  fmt.Sprintf("unexpected %q", c),
+		Line: dec.lineNum,
+		Pos:  dec.pos + 1,
+	}
+}
+
+// A SyntaxError represents a syntax error in the logfmt input stream.
+type SyntaxError struct {
+	Msg  string
+	Line int
+	Pos  int
+}
+
+func (e *SyntaxError) Error() string {
+	return fmt.Sprintf("logfmt syntax error at pos %d on line %d: %s", e.Pos, e.Line, e.Msg)
+}
diff --git a/vendor/github.com/go-logfmt/logfmt/doc.go b/vendor/github.com/go-logfmt/logfmt/doc.go
new file mode 100644
index 0000000..378e9ad
--- /dev/null
+++ b/vendor/github.com/go-logfmt/logfmt/doc.go
@@ -0,0 +1,6 @@
+// Package logfmt implements utilities to marshal and unmarshal data in the
+// logfmt format. The logfmt format records key/value pairs in a way that
+// balances readability for humans and simplicity of computer parsing. It is
+// most commonly used as a more human friendly alternative to JSON for
+// structured logging.
+package logfmt
diff --git a/vendor/github.com/go-logfmt/logfmt/encode.go b/vendor/github.com/go-logfmt/logfmt/encode.go
new file mode 100644
index 0000000..55f1603
--- /dev/null
+++ b/vendor/github.com/go-logfmt/logfmt/encode.go
@@ -0,0 +1,321 @@
+package logfmt
+
+import (
+	"bytes"
+	"encoding"
+	"errors"
+	"fmt"
+	"io"
+	"reflect"
+	"strings"
+	"unicode/utf8"
+)
+
+// MarshalKeyvals returns the logfmt encoding of keyvals, a variadic sequence
+// of alternating keys and values.
+func MarshalKeyvals(keyvals ...interface{}) ([]byte, error) {
+	buf := &bytes.Buffer{}
+	if err := NewEncoder(buf).EncodeKeyvals(keyvals...); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+// An Encoder writes logfmt data to an output stream.
+type Encoder struct {
+	w       io.Writer
+	scratch bytes.Buffer
+	needSep bool
+}
+
+// NewEncoder returns a new encoder that writes to w.
+func NewEncoder(w io.Writer) *Encoder {
+	return &Encoder{
+		w: w,
+	}
+}
+
+var (
+	space   = []byte(" ")
+	equals  = []byte("=")
+	newline = []byte("\n")
+	null    = []byte("null")
+)
+
+// EncodeKeyval writes the logfmt encoding of key and value to the stream. A
+// single space is written before the second and subsequent keys in a record.
+// Nothing is written if a non-nil error is returned.
+func (enc *Encoder) EncodeKeyval(key, value interface{}) error {
+	enc.scratch.Reset()
+	if enc.needSep {
+		if _, err := enc.scratch.Write(space); err != nil {
+			return err
+		}
+	}
+	if err := writeKey(&enc.scratch, key); err != nil {
+		return err
+	}
+	if _, err := enc.scratch.Write(equals); err != nil {
+		return err
+	}
+	if err := writeValue(&enc.scratch, value); err != nil {
+		return err
+	}
+	_, err := enc.w.Write(enc.scratch.Bytes())
+	enc.needSep = true
+	return err
+}
+
+// EncodeKeyvals writes the logfmt encoding of keyvals to the stream. Keyvals
+// is a variadic sequence of alternating keys and values. Keys of unsupported
+// type are skipped along with their corresponding value. Values of
+// unsupported type or that cause a MarshalerError are replaced by their error
+// but do not cause EncodeKeyvals to return an error. If a non-nil error is
+// returned some key/value pairs may not have be written.
+func (enc *Encoder) EncodeKeyvals(keyvals ...interface{}) error {
+	if len(keyvals) == 0 {
+		return nil
+	}
+	if len(keyvals)%2 == 1 {
+		keyvals = append(keyvals, nil)
+	}
+	for i := 0; i < len(keyvals); i += 2 {
+		k, v := keyvals[i], keyvals[i+1]
+		err := enc.EncodeKeyval(k, v)
+		if err == ErrUnsupportedKeyType {
+			continue
+		}
+		if _, ok := err.(*MarshalerError); ok || err == ErrUnsupportedValueType {
+			v = err
+			err = enc.EncodeKeyval(k, v)
+		}
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// MarshalerError represents an error encountered while marshaling a value.
+type MarshalerError struct {
+	Type reflect.Type
+	Err  error
+}
+
+func (e *MarshalerError) Error() string {
+	return "error marshaling value of type " + e.Type.String() + ": " + e.Err.Error()
+}
+
+// ErrNilKey is returned by Marshal functions and Encoder methods if a key is
+// a nil interface or pointer value.
+var ErrNilKey = errors.New("nil key")
+
+// ErrInvalidKey is returned by Marshal functions and Encoder methods if a key
+// contains an invalid character.
+var ErrInvalidKey = errors.New("invalid key")
+
+// ErrUnsupportedKeyType is returned by Encoder methods if a key has an
+// unsupported type.
+var ErrUnsupportedKeyType = errors.New("unsupported key type")
+
+// ErrUnsupportedValueType is returned by Encoder methods if a value has an
+// unsupported type.
+var ErrUnsupportedValueType = errors.New("unsupported value type")
+
+func writeKey(w io.Writer, key interface{}) error {
+	if key == nil {
+		return ErrNilKey
+	}
+
+	switch k := key.(type) {
+	case string:
+		return writeStringKey(w, k)
+	case []byte:
+		if k == nil {
+			return ErrNilKey
+		}
+		return writeBytesKey(w, k)
+	case encoding.TextMarshaler:
+		kb, err := safeMarshal(k)
+		if err != nil {
+			return err
+		}
+		if kb == nil {
+			return ErrNilKey
+		}
+		return writeBytesKey(w, kb)
+	case fmt.Stringer:
+		ks, ok := safeString(k)
+		if !ok {
+			return ErrNilKey
+		}
+		return writeStringKey(w, ks)
+	default:
+		rkey := reflect.ValueOf(key)
+		switch rkey.Kind() {
+		case reflect.Array, reflect.Chan, reflect.Func, reflect.Map, reflect.Slice, reflect.Struct:
+			return ErrUnsupportedKeyType
+		case reflect.Ptr:
+			if rkey.IsNil() {
+				return ErrNilKey
+			}
+			return writeKey(w, rkey.Elem().Interface())
+		}
+		return writeStringKey(w, fmt.Sprint(k))
+	}
+}
+
+func invalidKeyRune(r rune) bool {
+	return r <= ' ' || r == '=' || r == '"' || r == utf8.RuneError
+}
+
+func invalidKeyString(key string) bool {
+	return len(key) == 0 || strings.IndexFunc(key, invalidKeyRune) != -1
+}
+
+func invalidKey(key []byte) bool {
+	return len(key) == 0 || bytes.IndexFunc(key, invalidKeyRune) != -1
+}
+
+func writeStringKey(w io.Writer, key string) error {
+	if invalidKeyString(key) {
+		return ErrInvalidKey
+	}
+	_, err := io.WriteString(w, key)
+	return err
+}
+
+func writeBytesKey(w io.Writer, key []byte) error {
+	if invalidKey(key) {
+		return ErrInvalidKey
+	}
+	_, err := w.Write(key)
+	return err
+}
+
+func writeValue(w io.Writer, value interface{}) error {
+	switch v := value.(type) {
+	case nil:
+		return writeBytesValue(w, null)
+	case string:
+		return writeStringValue(w, v, true)
+	case []byte:
+		return writeBytesValue(w, v)
+	case encoding.TextMarshaler:
+		vb, err := safeMarshal(v)
+		if err != nil {
+			return err
+		}
+		if vb == nil {
+			vb = null
+		}
+		return writeBytesValue(w, vb)
+	case error:
+		se, ok := safeError(v)
+		return writeStringValue(w, se, ok)
+	case fmt.Stringer:
+		ss, ok := safeString(v)
+		return writeStringValue(w, ss, ok)
+	default:
+		rvalue := reflect.ValueOf(value)
+		switch rvalue.Kind() {
+		case reflect.Array, reflect.Chan, reflect.Func, reflect.Map, reflect.Slice, reflect.Struct:
+			return ErrUnsupportedValueType
+		case reflect.Ptr:
+			if rvalue.IsNil() {
+				return writeBytesValue(w, null)
+			}
+			return writeValue(w, rvalue.Elem().Interface())
+		}
+		return writeStringValue(w, fmt.Sprint(v), true)
+	}
+}
+
+func needsQuotedValueRune(r rune) bool {
+	return r <= ' ' || r == '=' || r == '"' || r == utf8.RuneError
+}
+
+func writeStringValue(w io.Writer, value string, ok bool) error {
+	var err error
+	if ok && value == "null" {
+		_, err = io.WriteString(w, `"null"`)
+	} else if strings.IndexFunc(value, needsQuotedValueRune) != -1 {
+		_, err = writeQuotedString(w, value)
+	} else {
+		_, err = io.WriteString(w, value)
+	}
+	return err
+}
+
+func writeBytesValue(w io.Writer, value []byte) error {
+	var err error
+	if bytes.IndexFunc(value, needsQuotedValueRune) != -1 {
+		_, err = writeQuotedBytes(w, value)
+	} else {
+		_, err = w.Write(value)
+	}
+	return err
+}
+
+// EndRecord writes a newline character to the stream and resets the encoder
+// to the beginning of a new record.
+func (enc *Encoder) EndRecord() error {
+	_, err := enc.w.Write(newline)
+	if err == nil {
+		enc.needSep = false
+	}
+	return err
+}
+
+// Reset resets the encoder to the beginning of a new record.
+func (enc *Encoder) Reset() {
+	enc.needSep = false
+}
+
+func safeError(err error) (s string, ok bool) {
+	defer func() {
+		if panicVal := recover(); panicVal != nil {
+			if v := reflect.ValueOf(err); v.Kind() == reflect.Ptr && v.IsNil() {
+				s, ok = "null", false
+			} else {
+				panic(panicVal)
+			}
+		}
+	}()
+	s, ok = err.Error(), true
+	return
+}
+
+func safeString(str fmt.Stringer) (s string, ok bool) {
+	defer func() {
+		if panicVal := recover(); panicVal != nil {
+			if v := reflect.ValueOf(str); v.Kind() == reflect.Ptr && v.IsNil() {
+				s, ok = "null", false
+			} else {
+				panic(panicVal)
+			}
+		}
+	}()
+	s, ok = str.String(), true
+	return
+}
+
+func safeMarshal(tm encoding.TextMarshaler) (b []byte, err error) {
+	defer func() {
+		if panicVal := recover(); panicVal != nil {
+			if v := reflect.ValueOf(tm); v.Kind() == reflect.Ptr && v.IsNil() {
+				b, err = nil, nil
+			} else {
+				panic(panicVal)
+			}
+		}
+	}()
+	b, err = tm.MarshalText()
+	if err != nil {
+		return nil, &MarshalerError{
+			Type: reflect.TypeOf(tm),
+			Err:  err,
+		}
+	}
+	return
+}
diff --git a/vendor/github.com/go-logfmt/logfmt/fuzz.go b/vendor/github.com/go-logfmt/logfmt/fuzz.go
new file mode 100644
index 0000000..6553b35
--- /dev/null
+++ b/vendor/github.com/go-logfmt/logfmt/fuzz.go
@@ -0,0 +1,126 @@
+// +build gofuzz
+
+package logfmt
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"reflect"
+
+	kr "github.com/kr/logfmt"
+)
+
+// Fuzz checks reserialized data matches
+func Fuzz(data []byte) int {
+	parsed, err := parse(data)
+	if err != nil {
+		return 0
+	}
+	var w1 bytes.Buffer
+	if err = write(parsed, &w1); err != nil {
+		panic(err)
+	}
+	parsed, err = parse(w1.Bytes())
+	if err != nil {
+		panic(err)
+	}
+	var w2 bytes.Buffer
+	if err = write(parsed, &w2); err != nil {
+		panic(err)
+	}
+	if !bytes.Equal(w1.Bytes(), w2.Bytes()) {
+		panic(fmt.Sprintf("reserialized data does not match:\n%q\n%q\n", w1.Bytes(), w2.Bytes()))
+	}
+	return 1
+}
+
+// FuzzVsKR checks go-logfmt/logfmt against kr/logfmt
+func FuzzVsKR(data []byte) int {
+	parsed, err := parse(data)
+	parsedKR, errKR := parseKR(data)
+
+	// github.com/go-logfmt/logfmt is a stricter parser. It returns errors for
+	// more inputs than github.com/kr/logfmt. Ignore any inputs that have a
+	// stict error.
+	if err != nil {
+		return 0
+	}
+
+	// Fail if the more forgiving parser finds an error not found by the
+	// stricter parser.
+	if errKR != nil {
+		panic(fmt.Sprintf("unmatched error: %v", errKR))
+	}
+
+	if !reflect.DeepEqual(parsed, parsedKR) {
+		panic(fmt.Sprintf("parsers disagree:\n%+v\n%+v\n", parsed, parsedKR))
+	}
+	return 1
+}
+
+type kv struct {
+	k, v []byte
+}
+
+func parse(data []byte) ([][]kv, error) {
+	var got [][]kv
+	dec := NewDecoder(bytes.NewReader(data))
+	for dec.ScanRecord() {
+		var kvs []kv
+		for dec.ScanKeyval() {
+			kvs = append(kvs, kv{dec.Key(), dec.Value()})
+		}
+		got = append(got, kvs)
+	}
+	return got, dec.Err()
+}
+
+func parseKR(data []byte) ([][]kv, error) {
+	var (
+		s   = bufio.NewScanner(bytes.NewReader(data))
+		err error
+		h   saveHandler
+		got [][]kv
+	)
+	for err == nil && s.Scan() {
+		h.kvs = nil
+		err = kr.Unmarshal(s.Bytes(), &h)
+		got = append(got, h.kvs)
+	}
+	if err == nil {
+		err = s.Err()
+	}
+	return got, err
+}
+
+type saveHandler struct {
+	kvs []kv
+}
+
+func (h *saveHandler) HandleLogfmt(key, val []byte) error {
+	if len(key) == 0 {
+		key = nil
+	}
+	if len(val) == 0 {
+		val = nil
+	}
+	h.kvs = append(h.kvs, kv{key, val})
+	return nil
+}
+
+func write(recs [][]kv, w io.Writer) error {
+	enc := NewEncoder(w)
+	for _, rec := range recs {
+		for _, f := range rec {
+			if err := enc.EncodeKeyval(f.k, f.v); err != nil {
+				return err
+			}
+		}
+		if err := enc.EndRecord(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
diff --git a/vendor/github.com/go-logfmt/logfmt/jsonstring.go b/vendor/github.com/go-logfmt/logfmt/jsonstring.go
new file mode 100644
index 0000000..030ac85
--- /dev/null
+++ b/vendor/github.com/go-logfmt/logfmt/jsonstring.go
@@ -0,0 +1,277 @@
+package logfmt
+
+import (
+	"bytes"
+	"io"
+	"strconv"
+	"sync"
+	"unicode"
+	"unicode/utf16"
+	"unicode/utf8"
+)
+
+// Taken from Go's encoding/json and modified for use here.
+
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+var hex = "0123456789abcdef"
+
+var bufferPool = sync.Pool{
+	New: func() interface{} {
+		return &bytes.Buffer{}
+	},
+}
+
+func getBuffer() *bytes.Buffer {
+	return bufferPool.Get().(*bytes.Buffer)
+}
+
+func poolBuffer(buf *bytes.Buffer) {
+	buf.Reset()
+	bufferPool.Put(buf)
+}
+
+// NOTE: keep in sync with writeQuotedBytes below.
+func writeQuotedString(w io.Writer, s string) (int, error) {
+	buf := getBuffer()
+	buf.WriteByte('"')
+	start := 0
+	for i := 0; i < len(s); {
+		if b := s[i]; b < utf8.RuneSelf {
+			if 0x20 <= b && b != '\\' && b != '"' {
+				i++
+				continue
+			}
+			if start < i {
+				buf.WriteString(s[start:i])
+			}
+			switch b {
+			case '\\', '"':
+				buf.WriteByte('\\')
+				buf.WriteByte(b)
+			case '\n':
+				buf.WriteByte('\\')
+				buf.WriteByte('n')
+			case '\r':
+				buf.WriteByte('\\')
+				buf.WriteByte('r')
+			case '\t':
+				buf.WriteByte('\\')
+				buf.WriteByte('t')
+			default:
+				// This encodes bytes < 0x20 except for \n, \r, and \t.
+				buf.WriteString(`\u00`)
+				buf.WriteByte(hex[b>>4])
+				buf.WriteByte(hex[b&0xF])
+			}
+			i++
+			start = i
+			continue
+		}
+		c, size := utf8.DecodeRuneInString(s[i:])
+		if c == utf8.RuneError {
+			if start < i {
+				buf.WriteString(s[start:i])
+			}
+			buf.WriteString(`\ufffd`)
+			i += size
+			start = i
+			continue
+		}
+		i += size
+	}
+	if start < len(s) {
+		buf.WriteString(s[start:])
+	}
+	buf.WriteByte('"')
+	n, err := w.Write(buf.Bytes())
+	poolBuffer(buf)
+	return n, err
+}
+
+// NOTE: keep in sync with writeQuoteString above.
+func writeQuotedBytes(w io.Writer, s []byte) (int, error) {
+	buf := getBuffer()
+	buf.WriteByte('"')
+	start := 0
+	for i := 0; i < len(s); {
+		if b := s[i]; b < utf8.RuneSelf {
+			if 0x20 <= b && b != '\\' && b != '"' {
+				i++
+				continue
+			}
+			if start < i {
+				buf.Write(s[start:i])
+			}
+			switch b {
+			case '\\', '"':
+				buf.WriteByte('\\')
+				buf.WriteByte(b)
+			case '\n':
+				buf.WriteByte('\\')
+				buf.WriteByte('n')
+			case '\r':
+				buf.WriteByte('\\')
+				buf.WriteByte('r')
+			case '\t':
+				buf.WriteByte('\\')
+				buf.WriteByte('t')
+			default:
+				// This encodes bytes < 0x20 except for \n, \r, and \t.
+				buf.WriteString(`\u00`)
+				buf.WriteByte(hex[b>>4])
+				buf.WriteByte(hex[b&0xF])
+			}
+			i++
+			start = i
+			continue
+		}
+		c, size := utf8.DecodeRune(s[i:])
+		if c == utf8.RuneError {
+			if start < i {
+				buf.Write(s[start:i])
+			}
+			buf.WriteString(`\ufffd`)
+			i += size
+			start = i
+			continue
+		}
+		i += size
+	}
+	if start < len(s) {
+		buf.Write(s[start:])
+	}
+	buf.WriteByte('"')
+	n, err := w.Write(buf.Bytes())
+	poolBuffer(buf)
+	return n, err
+}
+
+// getu4 decodes \uXXXX from the beginning of s, returning the hex value,
+// or it returns -1.
+func getu4(s []byte) rune {
+	if len(s) < 6 || s[0] != '\\' || s[1] != 'u' {
+		return -1
+	}
+	r, err := strconv.ParseUint(string(s[2:6]), 16, 64)
+	if err != nil {
+		return -1
+	}
+	return rune(r)
+}
+
+func unquoteBytes(s []byte) (t []byte, ok bool) {
+	if len(s) < 2 || s[0] != '"' || s[len(s)-1] != '"' {
+		return
+	}
+	s = s[1 : len(s)-1]
+
+	// Check for unusual characters. If there are none,
+	// then no unquoting is needed, so return a slice of the
+	// original bytes.
+	r := 0
+	for r < len(s) {
+		c := s[r]
+		if c == '\\' || c == '"' || c < ' ' {
+			break
+		}
+		if c < utf8.RuneSelf {
+			r++
+			continue
+		}
+		rr, size := utf8.DecodeRune(s[r:])
+		if rr == utf8.RuneError {
+			break
+		}
+		r += size
+	}
+	if r == len(s) {
+		return s, true
+	}
+
+	b := make([]byte, len(s)+2*utf8.UTFMax)
+	w := copy(b, s[0:r])
+	for r < len(s) {
+		// Out of room?  Can only happen if s is full of
+		// malformed UTF-8 and we're replacing each
+		// byte with RuneError.
+		if w >= len(b)-2*utf8.UTFMax {
+			nb := make([]byte, (len(b)+utf8.UTFMax)*2)
+			copy(nb, b[0:w])
+			b = nb
+		}
+		switch c := s[r]; {
+		case c == '\\':
+			r++
+			if r >= len(s) {
+				return
+			}
+			switch s[r] {
+			default:
+				return
+			case '"', '\\', '/', '\'':
+				b[w] = s[r]
+				r++
+				w++
+			case 'b':
+				b[w] = '\b'
+				r++
+				w++
+			case 'f':
+				b[w] = '\f'
+				r++
+				w++
+			case 'n':
+				b[w] = '\n'
+				r++
+				w++
+			case 'r':
+				b[w] = '\r'
+				r++
+				w++
+			case 't':
+				b[w] = '\t'
+				r++
+				w++
+			case 'u':
+				r--
+				rr := getu4(s[r:])
+				if rr < 0 {
+					return
+				}
+				r += 6
+				if utf16.IsSurrogate(rr) {
+					rr1 := getu4(s[r:])
+					if dec := utf16.DecodeRune(rr, rr1); dec != unicode.ReplacementChar {
+						// A valid pair; consume.
+						r += 6
+						w += utf8.EncodeRune(b[w:], dec)
+						break
+					}
+					// Invalid surrogate; fall back to replacement rune.
+					rr = unicode.ReplacementChar
+				}
+				w += utf8.EncodeRune(b[w:], rr)
+			}
+
+		// Quote, control characters are invalid.
+		case c == '"', c < ' ':
+			return
+
+		// ASCII
+		case c < utf8.RuneSelf:
+			b[w] = c
+			r++
+			w++
+
+		// Coerce to well-formed UTF-8.
+		default:
+			rr, size := utf8.DecodeRune(s[r:])
+			r += size
+			w += utf8.EncodeRune(b[w:], rr)
+		}
+	}
+	return b[0:w], true
+}
diff --git a/vendor/github.com/go-stack/stack/.travis.yml b/vendor/github.com/go-stack/stack/.travis.yml
new file mode 100644
index 0000000..e91cc9a
--- /dev/null
+++ b/vendor/github.com/go-stack/stack/.travis.yml
@@ -0,0 +1,13 @@
+language: go
+sudo: false
+go:
+  - 1.7
+  - 1.8
+  - 1.9
+  - tip
+
+before_install:
+  - go get github.com/mattn/goveralls
+
+script:
+  - goveralls -service=travis-ci
diff --git a/vendor/github.com/go-stack/stack/LICENSE.md b/vendor/github.com/go-stack/stack/LICENSE.md
new file mode 100644
index 0000000..2abf98e
--- /dev/null
+++ b/vendor/github.com/go-stack/stack/LICENSE.md
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2014 Chris Hines
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/vendor/github.com/go-stack/stack/README.md b/vendor/github.com/go-stack/stack/README.md
new file mode 100644
index 0000000..f11cccc
--- /dev/null
+++ b/vendor/github.com/go-stack/stack/README.md
@@ -0,0 +1,38 @@
+[![GoDoc](https://godoc.org/github.com/go-stack/stack?status.svg)](https://godoc.org/github.com/go-stack/stack)
+[![Go Report Card](https://goreportcard.com/badge/go-stack/stack)](https://goreportcard.com/report/go-stack/stack)
+[![TravisCI](https://travis-ci.org/go-stack/stack.svg?branch=master)](https://travis-ci.org/go-stack/stack)
+[![Coverage Status](https://coveralls.io/repos/github/go-stack/stack/badge.svg?branch=master)](https://coveralls.io/github/go-stack/stack?branch=master)
+
+# stack
+
+Package stack implements utilities to capture, manipulate, and format call
+stacks. It provides a simpler API than package runtime.
+
+The implementation takes care of the minutia and special cases of interpreting
+the program counter (pc) values returned by runtime.Callers.
+
+## Versioning
+
+Package stack publishes releases via [semver](http://semver.org/) compatible Git
+tags prefixed with a single 'v'. The master branch always contains the latest
+release. The develop branch contains unreleased commits.
+
+## Formatting
+
+Package stack's types implement fmt.Formatter, which provides a simple and
+flexible way to declaratively configure formatting when used with logging or
+error tracking packages.
+
+```go
+func DoTheThing() {
+    c := stack.Caller(0)
+    log.Print(c)          // "source.go:10"
+    log.Printf("%+v", c)  // "pkg/path/source.go:10"
+    log.Printf("%n", c)   // "DoTheThing"
+
+    s := stack.Trace().TrimRuntime()
+    log.Print(s)          // "[source.go:15 caller.go:42 main.go:14]"
+}
+```
+
+See the docs for all of the supported formatting options.
diff --git a/vendor/github.com/go-stack/stack/stack.go b/vendor/github.com/go-stack/stack/stack.go
new file mode 100644
index 0000000..1bc6971
--- /dev/null
+++ b/vendor/github.com/go-stack/stack/stack.go
@@ -0,0 +1,324 @@
+// +build go1.7
+
+// Package stack implements utilities to capture, manipulate, and format call
+// stacks. It provides a simpler API than package runtime.
+//
+// The implementation takes care of the minutia and special cases of
+// interpreting the program counter (pc) values returned by runtime.Callers.
+//
+// Package stack's types implement fmt.Formatter, which provides a simple and
+// flexible way to declaratively configure formatting when used with logging
+// or error tracking packages.
+package stack
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"runtime"
+	"strconv"
+	"strings"
+)
+
+// Call records a single function invocation from a goroutine stack.
+type Call struct {
+	frame runtime.Frame
+}
+
+// Caller returns a Call from the stack of the current goroutine. The argument
+// skip is the number of stack frames to ascend, with 0 identifying the
+// calling function.
+func Caller(skip int) Call {
+	// As of Go 1.9 we need room for up to three PC entries.
+	//
+	// 0. An entry for the stack frame prior to the target to check for
+	//    special handling needed if that prior entry is runtime.sigpanic.
+	// 1. A possible second entry to hold metadata about skipped inlined
+	//    functions. If inline functions were not skipped the target frame
+	//    PC will be here.
+	// 2. A third entry for the target frame PC when the second entry
+	//    is used for skipped inline functions.
+	var pcs [3]uintptr
+	n := runtime.Callers(skip+1, pcs[:])
+	frames := runtime.CallersFrames(pcs[:n])
+	frame, _ := frames.Next()
+	frame, _ = frames.Next()
+
+	return Call{
+		frame: frame,
+	}
+}
+
+// String implements fmt.Stinger. It is equivalent to fmt.Sprintf("%v", c).
+func (c Call) String() string {
+	return fmt.Sprint(c)
+}
+
+// MarshalText implements encoding.TextMarshaler. It formats the Call the same
+// as fmt.Sprintf("%v", c).
+func (c Call) MarshalText() ([]byte, error) {
+	if c.frame == (runtime.Frame{}) {
+		return nil, ErrNoFunc
+	}
+
+	buf := bytes.Buffer{}
+	fmt.Fprint(&buf, c)
+	return buf.Bytes(), nil
+}
+
+// ErrNoFunc means that the Call has a nil *runtime.Func. The most likely
+// cause is a Call with the zero value.
+var ErrNoFunc = errors.New("no call stack information")
+
+// Format implements fmt.Formatter with support for the following verbs.
+//
+//    %s    source file
+//    %d    line number
+//    %n    function name
+//    %k    last segment of the package path
+//    %v    equivalent to %s:%d
+//
+// It accepts the '+' and '#' flags for most of the verbs as follows.
+//
+//    %+s   path of source file relative to the compile time GOPATH
+//    %#s   full path of source file
+//    %+n   import path qualified function name
+//    %+k   full package path
+//    %+v   equivalent to %+s:%d
+//    %#v   equivalent to %#s:%d
+func (c Call) Format(s fmt.State, verb rune) {
+	if c.frame == (runtime.Frame{}) {
+		fmt.Fprintf(s, "%%!%c(NOFUNC)", verb)
+		return
+	}
+
+	switch verb {
+	case 's', 'v':
+		file := c.frame.File
+		switch {
+		case s.Flag('#'):
+			// done
+		case s.Flag('+'):
+			file = file[pkgIndex(file, c.frame.Function):]
+		default:
+			const sep = "/"
+			if i := strings.LastIndex(file, sep); i != -1 {
+				file = file[i+len(sep):]
+			}
+		}
+		io.WriteString(s, file)
+		if verb == 'v' {
+			buf := [7]byte{':'}
+			s.Write(strconv.AppendInt(buf[:1], int64(c.frame.Line), 10))
+		}
+
+	case 'd':
+		buf := [6]byte{}
+		s.Write(strconv.AppendInt(buf[:0], int64(c.frame.Line), 10))
+
+	case 'k':
+		name := c.frame.Function
+		const pathSep = "/"
+		start, end := 0, len(name)
+		if i := strings.LastIndex(name, pathSep); i != -1 {
+			start = i + len(pathSep)
+		}
+		const pkgSep = "."
+		if i := strings.Index(name[start:], pkgSep); i != -1 {
+			end = start + i
+		}
+		if s.Flag('+') {
+			start = 0
+		}
+		io.WriteString(s, name[start:end])
+
+	case 'n':
+		name := c.frame.Function
+		if !s.Flag('+') {
+			const pathSep = "/"
+			if i := strings.LastIndex(name, pathSep); i != -1 {
+				name = name[i+len(pathSep):]
+			}
+			const pkgSep = "."
+			if i := strings.Index(name, pkgSep); i != -1 {
+				name = name[i+len(pkgSep):]
+			}
+		}
+		io.WriteString(s, name)
+	}
+}
+
+// Frame returns the call frame infomation for the Call.
+func (c Call) Frame() runtime.Frame {
+	return c.frame
+}
+
+// PC returns the program counter for this call frame; multiple frames may
+// have the same PC value.
+//
+// Deprecated: Use Call.Frame instead.
+func (c Call) PC() uintptr {
+	return c.frame.PC
+}
+
+// CallStack records a sequence of function invocations from a goroutine
+// stack.
+type CallStack []Call
+
+// String implements fmt.Stinger. It is equivalent to fmt.Sprintf("%v", cs).
+func (cs CallStack) String() string {
+	return fmt.Sprint(cs)
+}
+
+var (
+	openBracketBytes  = []byte("[")
+	closeBracketBytes = []byte("]")
+	spaceBytes        = []byte(" ")
+)
+
+// MarshalText implements encoding.TextMarshaler. It formats the CallStack the
+// same as fmt.Sprintf("%v", cs).
+func (cs CallStack) MarshalText() ([]byte, error) {
+	buf := bytes.Buffer{}
+	buf.Write(openBracketBytes)
+	for i, pc := range cs {
+		if i > 0 {
+			buf.Write(spaceBytes)
+		}
+		fmt.Fprint(&buf, pc)
+	}
+	buf.Write(closeBracketBytes)
+	return buf.Bytes(), nil
+}
+
+// Format implements fmt.Formatter by printing the CallStack as square brackets
+// ([, ]) surrounding a space separated list of Calls each formatted with the
+// supplied verb and options.
+func (cs CallStack) Format(s fmt.State, verb rune) {
+	s.Write(openBracketBytes)
+	for i, pc := range cs {
+		if i > 0 {
+			s.Write(spaceBytes)
+		}
+		pc.Format(s, verb)
+	}
+	s.Write(closeBracketBytes)
+}
+
+// Trace returns a CallStack for the current goroutine with element 0
+// identifying the calling function.
+func Trace() CallStack {
+	var pcs [512]uintptr
+	n := runtime.Callers(1, pcs[:])
+
+	frames := runtime.CallersFrames(pcs[:n])
+	cs := make(CallStack, 0, n)
+
+	// Skip extra frame retrieved just to make sure the runtime.sigpanic
+	// special case is handled.
+	frame, more := frames.Next()
+
+	for more {
+		frame, more = frames.Next()
+		cs = append(cs, Call{frame: frame})
+	}
+
+	return cs
+}
+
+// TrimBelow returns a slice of the CallStack with all entries below c
+// removed.
+func (cs CallStack) TrimBelow(c Call) CallStack {
+	for len(cs) > 0 && cs[0] != c {
+		cs = cs[1:]
+	}
+	return cs
+}
+
+// TrimAbove returns a slice of the CallStack with all entries above c
+// removed.
+func (cs CallStack) TrimAbove(c Call) CallStack {
+	for len(cs) > 0 && cs[len(cs)-1] != c {
+		cs = cs[:len(cs)-1]
+	}
+	return cs
+}
+
+// pkgIndex returns the index that results in file[index:] being the path of
+// file relative to the compile time GOPATH, and file[:index] being the
+// $GOPATH/src/ portion of file. funcName must be the name of a function in
+// file as returned by runtime.Func.Name.
+func pkgIndex(file, funcName string) int {
+	// As of Go 1.6.2 there is no direct way to know the compile time GOPATH
+	// at runtime, but we can infer the number of path segments in the GOPATH.
+	// We note that runtime.Func.Name() returns the function name qualified by
+	// the import path, which does not include the GOPATH. Thus we can trim
+	// segments from the beginning of the file path until the number of path
+	// separators remaining is one more than the number of path separators in
+	// the function name. For example, given:
+	//
+	//    GOPATH     /home/user
+	//    file       /home/user/src/pkg/sub/file.go
+	//    fn.Name()  pkg/sub.Type.Method
+	//
+	// We want to produce:
+	//
+	//    file[:idx] == /home/user/src/
+	//    file[idx:] == pkg/sub/file.go
+	//
+	// From this we can easily see that fn.Name() has one less path separator
+	// than our desired result for file[idx:]. We count separators from the
+	// end of the file path until it finds two more than in the function name
+	// and then move one character forward to preserve the initial path
+	// segment without a leading separator.
+	const sep = "/"
+	i := len(file)
+	for n := strings.Count(funcName, sep) + 2; n > 0; n-- {
+		i = strings.LastIndex(file[:i], sep)
+		if i == -1 {
+			i = -len(sep)
+			break
+		}
+	}
+	// get back to 0 or trim the leading separator
+	return i + len(sep)
+}
+
+var runtimePath string
+
+func init() {
+	var pcs [3]uintptr
+	runtime.Callers(0, pcs[:])
+	frames := runtime.CallersFrames(pcs[:])
+	frame, _ := frames.Next()
+	file := frame.File
+
+	idx := pkgIndex(frame.File, frame.Function)
+
+	runtimePath = file[:idx]
+	if runtime.GOOS == "windows" {
+		runtimePath = strings.ToLower(runtimePath)
+	}
+}
+
+func inGoroot(c Call) bool {
+	file := c.frame.File
+	if len(file) == 0 || file[0] == '?' {
+		return true
+	}
+	if runtime.GOOS == "windows" {
+		file = strings.ToLower(file)
+	}
+	return strings.HasPrefix(file, runtimePath) || strings.HasSuffix(file, "/_testmain.go")
+}
+
+// TrimRuntime returns a slice of the CallStack with the topmost entries from
+// the go runtime removed. It considers any calls originating from unknown
+// files, files under GOROOT, or _testmain.go as part of the runtime.
+func (cs CallStack) TrimRuntime() CallStack {
+	for len(cs) > 0 && inGoroot(cs[len(cs)-1]) {
+		cs = cs[:len(cs)-1]
+	}
+	return cs
+}
diff --git a/vendor/github.com/gorilla/context/.travis.yml b/vendor/github.com/gorilla/context/.travis.yml
new file mode 100644
index 0000000..faca4da
--- /dev/null
+++ b/vendor/github.com/gorilla/context/.travis.yml
@@ -0,0 +1,19 @@
+language: go
+sudo: false
+
+matrix:
+  include:
+    - go: 1.3
+    - go: 1.4
+    - go: 1.5
+    - go: 1.6
+    - go: tip
+
+install:
+  - go get golang.org/x/tools/cmd/vet
+
+script:
+  - go get -t -v ./...
+  - diff -u <(echo -n) <(gofmt -d .)
+  - go tool vet .
+  - go test -v -race ./...
diff --git a/vendor/github.com/gorilla/context/LICENSE b/vendor/github.com/gorilla/context/LICENSE
new file mode 100644
index 0000000..0e5fb87
--- /dev/null
+++ b/vendor/github.com/gorilla/context/LICENSE
@@ -0,0 +1,27 @@
+Copyright (c) 2012 Rodrigo Moraes. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+	 * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+	 * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+	 * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/github.com/gorilla/context/README.md b/vendor/github.com/gorilla/context/README.md
new file mode 100644
index 0000000..c60a31b
--- /dev/null
+++ b/vendor/github.com/gorilla/context/README.md
@@ -0,0 +1,7 @@
+context
+=======
+[![Build Status](https://travis-ci.org/gorilla/context.png?branch=master)](https://travis-ci.org/gorilla/context)
+
+gorilla/context is a general purpose registry for global request variables.
+
+Read the full documentation here: http://www.gorillatoolkit.org/pkg/context
diff --git a/vendor/github.com/gorilla/context/context.go b/vendor/github.com/gorilla/context/context.go
new file mode 100644
index 0000000..81cb128
--- /dev/null
+++ b/vendor/github.com/gorilla/context/context.go
@@ -0,0 +1,143 @@
+// Copyright 2012 The Gorilla Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package context
+
+import (
+	"net/http"
+	"sync"
+	"time"
+)
+
+var (
+	mutex sync.RWMutex
+	data  = make(map[*http.Request]map[interface{}]interface{})
+	datat = make(map[*http.Request]int64)
+)
+
+// Set stores a value for a given key in a given request.
+func Set(r *http.Request, key, val interface{}) {
+	mutex.Lock()
+	if data[r] == nil {
+		data[r] = make(map[interface{}]interface{})
+		datat[r] = time.Now().Unix()
+	}
+	data[r][key] = val
+	mutex.Unlock()
+}
+
+// Get returns a value stored for a given key in a given request.
+func Get(r *http.Request, key interface{}) interface{} {
+	mutex.RLock()
+	if ctx := data[r]; ctx != nil {
+		value := ctx[key]
+		mutex.RUnlock()
+		return value
+	}
+	mutex.RUnlock()
+	return nil
+}
+
+// GetOk returns stored value and presence state like multi-value return of map access.
+func GetOk(r *http.Request, key interface{}) (interface{}, bool) {
+	mutex.RLock()
+	if _, ok := data[r]; ok {
+		value, ok := data[r][key]
+		mutex.RUnlock()
+		return value, ok
+	}
+	mutex.RUnlock()
+	return nil, false
+}
+
+// GetAll returns all stored values for the request as a map. Nil is returned for invalid requests.
+func GetAll(r *http.Request) map[interface{}]interface{} {
+	mutex.RLock()
+	if context, ok := data[r]; ok {
+		result := make(map[interface{}]interface{}, len(context))
+		for k, v := range context {
+			result[k] = v
+		}
+		mutex.RUnlock()
+		return result
+	}
+	mutex.RUnlock()
+	return nil
+}
+
+// GetAllOk returns all stored values for the request as a map and a boolean value that indicates if
+// the request was registered.
+func GetAllOk(r *http.Request) (map[interface{}]interface{}, bool) {
+	mutex.RLock()
+	context, ok := data[r]
+	result := make(map[interface{}]interface{}, len(context))
+	for k, v := range context {
+		result[k] = v
+	}
+	mutex.RUnlock()
+	return result, ok
+}
+
+// Delete removes a value stored for a given key in a given request.
+func Delete(r *http.Request, key interface{}) {
+	mutex.Lock()
+	if data[r] != nil {
+		delete(data[r], key)
+	}
+	mutex.Unlock()
+}
+
+// Clear removes all values stored for a given request.
+//
+// This is usually called by a handler wrapper to clean up request
+// variables at the end of a request lifetime. See ClearHandler().
+func Clear(r *http.Request) {
+	mutex.Lock()
+	clear(r)
+	mutex.Unlock()
+}
+
+// clear is Clear without the lock.
+func clear(r *http.Request) {
+	delete(data, r)
+	delete(datat, r)
+}
+
+// Purge removes request data stored for longer than maxAge, in seconds.
+// It returns the amount of requests removed.
+//
+// If maxAge <= 0, all request data is removed.
+//
+// This is only used for sanity check: in case context cleaning was not
+// properly set some request data can be kept forever, consuming an increasing
+// amount of memory. In case this is detected, Purge() must be called
+// periodically until the problem is fixed.
+func Purge(maxAge int) int {
+	mutex.Lock()
+	count := 0
+	if maxAge <= 0 {
+		count = len(data)
+		data = make(map[*http.Request]map[interface{}]interface{})
+		datat = make(map[*http.Request]int64)
+	} else {
+		min := time.Now().Unix() - int64(maxAge)
+		for r := range data {
+			if datat[r] < min {
+				clear(r)
+				count++
+			}
+		}
+	}
+	mutex.Unlock()
+	return count
+}
+
+// ClearHandler wraps an http.Handler and clears request values at the end
+// of a request lifetime.
+func ClearHandler(h http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		defer Clear(r)
+		h.ServeHTTP(w, r)
+	})
+}
diff --git a/vendor/github.com/gorilla/context/doc.go b/vendor/github.com/gorilla/context/doc.go
new file mode 100644
index 0000000..73c7400
--- /dev/null
+++ b/vendor/github.com/gorilla/context/doc.go
@@ -0,0 +1,82 @@
+// Copyright 2012 The Gorilla Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+Package context stores values shared during a request lifetime.
+
+For example, a router can set variables extracted from the URL and later
+application handlers can access those values, or it can be used to store
+sessions values to be saved at the end of a request. There are several
+others common uses.
+
+The idea was posted by Brad Fitzpatrick to the go-nuts mailing list:
+
+	http://groups.google.com/group/golang-nuts/msg/e2d679d303aa5d53
+
+Here's the basic usage: first define the keys that you will need. The key
+type is interface{} so a key can be of any type that supports equality.
+Here we define a key using a custom int type to avoid name collisions:
+
+	package foo
+
+	import (
+		"github.com/gorilla/context"
+	)
+
+	type key int
+
+	const MyKey key = 0
+
+Then set a variable. Variables are bound to an http.Request object, so you
+need a request instance to set a value:
+
+	context.Set(r, MyKey, "bar")
+
+The application can later access the variable using the same key you provided:
+
+	func MyHandler(w http.ResponseWriter, r *http.Request) {
+		// val is "bar".
+		val := context.Get(r, foo.MyKey)
+
+		// returns ("bar", true)
+		val, ok := context.GetOk(r, foo.MyKey)
+		// ...
+	}
+
+And that's all about the basic usage. We discuss some other ideas below.
+
+Any type can be stored in the context. To enforce a given type, make the key
+private and wrap Get() and Set() to accept and return values of a specific
+type:
+
+	type key int
+
+	const mykey key = 0
+
+	// GetMyKey returns a value for this package from the request values.
+	func GetMyKey(r *http.Request) SomeType {
+		if rv := context.Get(r, mykey); rv != nil {
+			return rv.(SomeType)
+		}
+		return nil
+	}
+
+	// SetMyKey sets a value for this package in the request values.
+	func SetMyKey(r *http.Request, val SomeType) {
+		context.Set(r, mykey, val)
+	}
+
+Variables must be cleared at the end of a request, to remove all values
+that were stored. This can be done in an http.Handler, after a request was
+served. Just call Clear() passing the request:
+
+	context.Clear(r)
+
+...or use ClearHandler(), which conveniently wraps an http.Handler to clear
+variables at the end of a request lifetime.
+
+The Routers from the packages gorilla/mux and gorilla/pat call Clear()
+so if you are using either of them you don't need to clear the context manually.
+*/
+package context
diff --git a/vendor/github.com/gorilla/mux/.travis.yml b/vendor/github.com/gorilla/mux/.travis.yml
new file mode 100644
index 0000000..3302233
--- /dev/null
+++ b/vendor/github.com/gorilla/mux/.travis.yml
@@ -0,0 +1,22 @@
+language: go
+sudo: false
+
+matrix:
+  include:
+    - go: 1.5
+    - go: 1.6
+    - go: 1.7
+    - go: 1.8
+    - go: 1.9
+    - go: tip
+  allow_failures:
+    - go: tip
+
+install:
+  - # Skip
+
+script:
+  - go get -t -v ./...
+  - diff -u <(echo -n) <(gofmt -d .)
+  - go tool vet .
+  - go test -v -race ./...
diff --git a/vendor/github.com/gorilla/mux/ISSUE_TEMPLATE.md b/vendor/github.com/gorilla/mux/ISSUE_TEMPLATE.md
new file mode 100644
index 0000000..232be82
--- /dev/null
+++ b/vendor/github.com/gorilla/mux/ISSUE_TEMPLATE.md
@@ -0,0 +1,11 @@
+**What version of Go are you running?** (Paste the output of `go version`)
+
+
+**What version of gorilla/mux are you at?** (Paste the output of `git rev-parse HEAD` inside `$GOPATH/src/github.com/gorilla/mux`)
+
+
+**Describe your problem** (and what you have tried so far)
+
+
+**Paste a minimal, runnable, reproduction of your issue below** (use backticks to format it)
+
diff --git a/vendor/github.com/gorilla/mux/LICENSE b/vendor/github.com/gorilla/mux/LICENSE
new file mode 100644
index 0000000..0e5fb87
--- /dev/null
+++ b/vendor/github.com/gorilla/mux/LICENSE
@@ -0,0 +1,27 @@
+Copyright (c) 2012 Rodrigo Moraes. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+	 * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+	 * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+	 * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/github.com/gorilla/mux/README.md b/vendor/github.com/gorilla/mux/README.md
new file mode 100644
index 0000000..f9b3103
--- /dev/null
+++ b/vendor/github.com/gorilla/mux/README.md
@@ -0,0 +1,560 @@
+gorilla/mux
+===
+[![GoDoc](https://godoc.org/github.com/gorilla/mux?status.svg)](https://godoc.org/github.com/gorilla/mux)
+[![Build Status](https://travis-ci.org/gorilla/mux.svg?branch=master)](https://travis-ci.org/gorilla/mux)
+[![Sourcegraph](https://sourcegraph.com/github.com/gorilla/mux/-/badge.svg)](https://sourcegraph.com/github.com/gorilla/mux?badge)
+
+![Gorilla Logo](http://www.gorillatoolkit.org/static/images/gorilla-icon-64.png)
+
+http://www.gorillatoolkit.org/pkg/mux
+
+Package `gorilla/mux` implements a request router and dispatcher for matching incoming requests to
+their respective handler.
+
+The name mux stands for "HTTP request multiplexer". Like the standard `http.ServeMux`, `mux.Router` matches incoming requests against a list of registered routes and calls a handler for the route that matches the URL or other conditions. The main features are:
+
+* It implements the `http.Handler` interface so it is compatible with the standard `http.ServeMux`.
+* Requests can be matched based on URL host, path, path prefix, schemes, header and query values, HTTP methods or using custom matchers.
+* URL hosts, paths and query values can have variables with an optional regular expression.
+* Registered URLs can be built, or "reversed", which helps maintaining references to resources.
+* Routes can be used as subrouters: nested routes are only tested if the parent route matches. This is useful to define groups of routes that share common conditions like a host, a path prefix or other repeated attributes. As a bonus, this optimizes request matching.
+
+---
+
+* [Install](#install)
+* [Examples](#examples)
+* [Matching Routes](#matching-routes)
+* [Static Files](#static-files)
+* [Registered URLs](#registered-urls)
+* [Walking Routes](#walking-routes)
+* [Graceful Shutdown](#graceful-shutdown)
+* [Middleware](#middleware)
+* [Full Example](#full-example)
+
+---
+
+## Install
+
+With a [correctly configured](https://golang.org/doc/install#testing) Go toolchain:
+
+```sh
+go get -u github.com/gorilla/mux
+```
+
+## Examples
+
+Let's start registering a couple of URL paths and handlers:
+
+```go
+func main() {
+    r := mux.NewRouter()
+    r.HandleFunc("/", HomeHandler)
+    r.HandleFunc("/products", ProductsHandler)
+    r.HandleFunc("/articles", ArticlesHandler)
+    http.Handle("/", r)
+}
+```
+
+Here we register three routes mapping URL paths to handlers. This is equivalent to how `http.HandleFunc()` works: if an incoming request URL matches one of the paths, the corresponding handler is called passing (`http.ResponseWriter`, `*http.Request`) as parameters.
+
+Paths can have variables. They are defined using the format `{name}` or `{name:pattern}`. If a regular expression pattern is not defined, the matched variable will be anything until the next slash. For example:
+
+```go
+r := mux.NewRouter()
+r.HandleFunc("/products/{key}", ProductHandler)
+r.HandleFunc("/articles/{category}/", ArticlesCategoryHandler)
+r.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler)
+```
+
+The names are used to create a map of route variables which can be retrieved calling `mux.Vars()`:
+
+```go
+func ArticlesCategoryHandler(w http.ResponseWriter, r *http.Request) {
+    vars := mux.Vars(r)
+    w.WriteHeader(http.StatusOK)
+    fmt.Fprintf(w, "Category: %v\n", vars["category"])
+}
+```
+
+And this is all you need to know about the basic usage. More advanced options are explained below.
+
+### Matching Routes
+
+Routes can also be restricted to a domain or subdomain. Just define a host pattern to be matched. They can also have variables:
+
+```go
+r := mux.NewRouter()
+// Only matches if domain is "www.example.com".
+r.Host("www.example.com")
+// Matches a dynamic subdomain.
+r.Host("{subdomain:[a-z]+}.domain.com")
+```
+
+There are several other matchers that can be added. To match path prefixes:
+
+```go
+r.PathPrefix("/products/")
+```
+
+...or HTTP methods:
+
+```go
+r.Methods("GET", "POST")
+```
+
+...or URL schemes:
+
+```go
+r.Schemes("https")
+```
+
+...or header values:
+
+```go
+r.Headers("X-Requested-With", "XMLHttpRequest")
+```
+
+...or query values:
+
+```go
+r.Queries("key", "value")
+```
+
+...or to use a custom matcher function:
+
+```go
+r.MatcherFunc(func(r *http.Request, rm *RouteMatch) bool {
+    return r.ProtoMajor == 0
+})
+```
+
+...and finally, it is possible to combine several matchers in a single route:
+
+```go
+r.HandleFunc("/products", ProductsHandler).
+  Host("www.example.com").
+  Methods("GET").
+  Schemes("http")
+```
+
+Routes are tested in the order they were added to the router. If two routes match, the first one wins:
+
+```go
+r := mux.NewRouter()
+r.HandleFunc("/specific", specificHandler)
+r.PathPrefix("/").Handler(catchAllHandler)
+```
+
+Setting the same matching conditions again and again can be boring, so we have a way to group several routes that share the same requirements. We call it "subrouting".
+
+For example, let's say we have several URLs that should only match when the host is `www.example.com`. Create a route for that host and get a "subrouter" from it:
+
+```go
+r := mux.NewRouter()
+s := r.Host("www.example.com").Subrouter()
+```
+
+Then register routes in the subrouter:
+
+```go
+s.HandleFunc("/products/", ProductsHandler)
+s.HandleFunc("/products/{key}", ProductHandler)
+s.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler)
+```
+
+The three URL paths we registered above will only be tested if the domain is `www.example.com`, because the subrouter is tested first. This is not only convenient, but also optimizes request matching. You can create subrouters combining any attribute matchers accepted by a route.
+
+Subrouters can be used to create domain or path "namespaces": you define subrouters in a central place and then parts of the app can register its paths relatively to a given subrouter.
+
+There's one more thing about subroutes. When a subrouter has a path prefix, the inner routes use it as base for their paths:
+
+```go
+r := mux.NewRouter()
+s := r.PathPrefix("/products").Subrouter()
+// "/products/"
+s.HandleFunc("/", ProductsHandler)
+// "/products/{key}/"
+s.HandleFunc("/{key}/", ProductHandler)
+// "/products/{key}/details"
+s.HandleFunc("/{key}/details", ProductDetailsHandler)
+```
+### Listing Routes
+
+Routes on a mux can be listed using the Router.Walk method—useful for generating documentation:
+
+```go
+package main
+
+import (
+    "fmt"
+    "net/http"
+    "strings"
+
+    "github.com/gorilla/mux"
+)
+
+func handler(w http.ResponseWriter, r *http.Request) {
+    return
+}
+
+func main() {
+    r := mux.NewRouter()
+    r.HandleFunc("/", handler)
+    r.HandleFunc("/products", handler).Methods("POST")
+    r.HandleFunc("/articles", handler).Methods("GET")
+    r.HandleFunc("/articles/{id}", handler).Methods("GET", "PUT")
+    r.HandleFunc("/authors", handler).Queries("surname", "{surname}")
+    r.Walk(func(route *mux.Route, router *mux.Router, ancestors []*mux.Route) error {
+        t, err := route.GetPathTemplate()
+        if err != nil {
+            return err
+        }
+        qt, err := route.GetQueriesTemplates()
+        if err != nil {
+            return err
+        }
+        // p will contain regular expression is compatible with regular expression in Perl, Python, and other languages.
+        // for instance the regular expression for path '/articles/{id}' will be '^/articles/(?P<v0>[^/]+)$'
+        p, err := route.GetPathRegexp()
+        if err != nil {
+            return err
+        }
+        // qr will contain a list of regular expressions with the same semantics as GetPathRegexp,
+        // just applied to the Queries pairs instead, e.g., 'Queries("surname", "{surname}") will return
+        // {"^surname=(?P<v0>.*)$}. Where each combined query pair will have an entry in the list.
+        qr, err := route.GetQueriesRegexp()
+        if err != nil {
+            return err
+        }
+        m, err := route.GetMethods()
+        if err != nil {
+            return err
+        }
+        fmt.Println(strings.Join(m, ","), strings.Join(qt, ","), strings.Join(qr, ","), t, p)
+        return nil
+    })
+    http.Handle("/", r)
+}
+```
+
+### Static Files
+
+Note that the path provided to `PathPrefix()` represents a "wildcard": calling
+`PathPrefix("/static/").Handler(...)` means that the handler will be passed any
+request that matches "/static/*". This makes it easy to serve static files with mux:
+
+```go
+func main() {
+    var dir string
+
+    flag.StringVar(&dir, "dir", ".", "the directory to serve files from. Defaults to the current dir")
+    flag.Parse()
+    r := mux.NewRouter()
+
+    // This will serve files under http://localhost:8000/static/<filename>
+    r.PathPrefix("/static/").Handler(http.StripPrefix("/static/", http.FileServer(http.Dir(dir))))
+
+    srv := &http.Server{
+        Handler:      r,
+        Addr:         "127.0.0.1:8000",
+        // Good practice: enforce timeouts for servers you create!
+        WriteTimeout: 15 * time.Second,
+        ReadTimeout:  15 * time.Second,
+    }
+
+    log.Fatal(srv.ListenAndServe())
+}
+```
+
+### Registered URLs
+
+Now let's see how to build registered URLs.
+
+Routes can be named. All routes that define a name can have their URLs built, or "reversed". We define a name calling `Name()` on a route. For example:
+
+```go
+r := mux.NewRouter()
+r.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler).
+  Name("article")
+```
+
+To build a URL, get the route and call the `URL()` method, passing a sequence of key/value pairs for the route variables. For the previous route, we would do:
+
+```go
+url, err := r.Get("article").URL("category", "technology", "id", "42")
+```
+
+...and the result will be a `url.URL` with the following path:
+
+```
+"/articles/technology/42"
+```
+
+This also works for host and query value variables:
+
+```go
+r := mux.NewRouter()
+r.Host("{subdomain}.domain.com").
+  Path("/articles/{category}/{id:[0-9]+}").
+  Queries("filter", "{filter}").
+  HandlerFunc(ArticleHandler).
+  Name("article")
+
+// url.String() will be "http://news.domain.com/articles/technology/42?filter=gorilla"
+url, err := r.Get("article").URL("subdomain", "news",
+                                 "category", "technology",
+                                 "id", "42",
+                                 "filter", "gorilla")
+```
+
+All variables defined in the route are required, and their values must conform to the corresponding patterns. These requirements guarantee that a generated URL will always match a registered route -- the only exception is for explicitly defined "build-only" routes which never match.
+
+Regex support also exists for matching Headers within a route. For example, we could do:
+
+```go
+r.HeadersRegexp("Content-Type", "application/(text|json)")
+```
+
+...and the route will match both requests with a Content-Type of `application/json` as well as `application/text`
+
+There's also a way to build only the URL host or path for a route: use the methods `URLHost()` or `URLPath()` instead. For the previous route, we would do:
+
+```go
+// "http://news.domain.com/"
+host, err := r.Get("article").URLHost("subdomain", "news")
+
+// "/articles/technology/42"
+path, err := r.Get("article").URLPath("category", "technology", "id", "42")
+```
+
+And if you use subrouters, host and path defined separately can be built as well:
+
+```go
+r := mux.NewRouter()
+s := r.Host("{subdomain}.domain.com").Subrouter()
+s.Path("/articles/{category}/{id:[0-9]+}").
+  HandlerFunc(ArticleHandler).
+  Name("article")
+
+// "http://news.domain.com/articles/technology/42"
+url, err := r.Get("article").URL("subdomain", "news",
+                                 "category", "technology",
+                                 "id", "42")
+```
+
+### Walking Routes
+
+The `Walk` function on `mux.Router` can be used to visit all of the routes that are registered on a router. For example,
+the following prints all of the registered routes:
+
+```go
+r := mux.NewRouter()
+r.HandleFunc("/", handler)
+r.HandleFunc("/products", handler).Methods("POST")
+r.HandleFunc("/articles", handler).Methods("GET")
+r.HandleFunc("/articles/{id}", handler).Methods("GET", "PUT")
+r.HandleFunc("/authors", handler).Queries("surname", "{surname}")
+r.Walk(func(route *mux.Route, router *mux.Router, ancestors []*mux.Route) error {
+    t, err := route.GetPathTemplate()
+    if err != nil {
+        return err
+    }
+    qt, err := route.GetQueriesTemplates()
+    if err != nil {
+        return err
+    }
+    // p will contain a regular expression that is compatible with regular expressions in Perl, Python, and other languages.
+    // For example, the regular expression for path '/articles/{id}' will be '^/articles/(?P<v0>[^/]+)$'.
+    p, err := route.GetPathRegexp()
+    if err != nil {
+        return err
+    }
+    // qr will contain a list of regular expressions with the same semantics as GetPathRegexp,
+    // just applied to the Queries pairs instead, e.g., 'Queries("surname", "{surname}") will return
+    // {"^surname=(?P<v0>.*)$}. Where each combined query pair will have an entry in the list.
+    qr, err := route.GetQueriesRegexp()
+    if err != nil {
+        return err
+    }
+    m, err := route.GetMethods()
+    if err != nil {
+        return err
+    }
+    fmt.Println(strings.Join(m, ","), strings.Join(qt, ","), strings.Join(qr, ","), t, p)
+    return nil
+})
+```
+
+### Graceful Shutdown
+
+Go 1.8 introduced the ability to [gracefully shutdown](https://golang.org/doc/go1.8#http_shutdown) a `*http.Server`. Here's how to do that alongside `mux`:
+
+```go
+package main
+
+import (
+    "context"
+    "flag"
+    "log"
+    "net/http"
+    "os"
+    "os/signal"
+
+    "github.com/gorilla/mux"
+)
+
+func main() {
+    var wait time.Duration
+    flag.DurationVar(&wait, "graceful-timeout", time.Second * 15, "the duration for which the server gracefully wait for existing connections to finish - e.g. 15s or 1m")
+    flag.Parse()
+
+    r := mux.NewRouter()
+    // Add your routes as needed
+    
+    srv := &http.Server{
+        Addr:         "0.0.0.0:8080",
+        // Good practice to set timeouts to avoid Slowloris attacks.
+        WriteTimeout: time.Second * 15,
+        ReadTimeout:  time.Second * 15,
+        IdleTimeout:  time.Second * 60,
+        Handler: r, // Pass our instance of gorilla/mux in.
+    }
+
+    // Run our server in a goroutine so that it doesn't block.
+    go func() {
+        if err := srv.ListenAndServe(); err != nil {
+            log.Println(err)
+        }
+    }()
+    
+    c := make(chan os.Signal, 1)
+    // We'll accept graceful shutdowns when quit via SIGINT (Ctrl+C)
+    // SIGKILL, SIGQUIT or SIGTERM (Ctrl+/) will not be caught.
+    signal.Notify(c, os.Interrupt)
+
+    // Block until we receive our signal.
+    <-c
+
+    // Create a deadline to wait for.
+    ctx, cancel := context.WithTimeout(ctx, wait)
+    // Doesn't block if no connections, but will otherwise wait
+    // until the timeout deadline.
+    srv.Shutdown(ctx)
+    // Optionally, you could run srv.Shutdown in a goroutine and block on
+    // <-ctx.Done() if your application should wait for other services
+    // to finalize based on context cancellation.
+    log.Println("shutting down")
+    os.Exit(0)
+}
+```
+
+### Middleware
+
+Mux supports the addition of middlewares to a [Router](https://godoc.org/github.com/gorilla/mux#Router), which are executed in the order they are added if a match is found, including its subrouters.
+Middlewares are (typically) small pieces of code which take one request, do something with it, and pass it down to another middleware or the final handler. Some common use cases for middleware are request logging, header manipulation, or `ResponseWriter` hijacking.
+
+Mux middlewares are defined using the de facto standard type:
+
+```go
+type MiddlewareFunc func(http.Handler) http.Handler
+```
+
+Typically, the returned handler is a closure which does something with the http.ResponseWriter and http.Request passed to it, and then calls the handler passed as parameter to the MiddlewareFunc. This takes advantage of closures being able access variables from the context where they are created, while retaining the signature enforced by the receivers.
+
+A very basic middleware which logs the URI of the request being handled could be written as:
+
+```go
+func simpleMw(next http.Handler) http.Handler {
+    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+        // Do stuff here
+        log.Println(r.RequestURI)
+        // Call the next handler, which can be another middleware in the chain, or the final handler.
+        next.ServeHTTP(w, r)
+    })
+}
+```
+
+Middlewares can be added to a router using `Router.AddMiddlewareFunc()`:
+
+```go
+r := mux.NewRouter()
+r.HandleFunc("/", handler)
+r.AddMiddleware(simpleMw)
+```
+
+A more complex authentication middleware, which maps session token to users, could be written as:
+
+```go
+// Define our struct
+type authenticationMiddleware struct {
+	tokenUsers map[string]string
+}
+
+// Initialize it somewhere
+func (amw *authenticationMiddleware) Populate() {
+	amw.tokenUsers["00000000"] = "user0"
+	amw.tokenUsers["aaaaaaaa"] = "userA"
+	amw.tokenUsers["05f717e5"] = "randomUser"
+	amw.tokenUsers["deadbeef"] = "user0"
+}
+
+// Middleware function, which will be called for each request
+func (amw *authenticationMiddleware) Middleware(next http.Handler) http.Handler {
+    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+        token := r.Header.Get("X-Session-Token")
+        
+        if user, found := amw.tokenUsers[token]; found {
+        	// We found the token in our map
+        	log.Printf("Authenticated user %s\n", user)
+        	// Pass down the request to the next middleware (or final handler)
+        	next.ServeHTTP(w, r)
+        } else {
+        	// Write an error and stop the handler chain
+        	http.Error(w, "Forbidden", 403)
+        }
+    })
+}
+```
+
+```go
+r := mux.NewRouter()
+r.HandleFunc("/", handler)
+
+amw := authenticationMiddleware{}
+amw.Populate()
+
+r.AddMiddlewareFunc(amw.Middleware)
+```
+
+Note: The handler chain will be stopped if your middleware doesn't call `next.ServeHTTP()` with the corresponding parameters. This can be used to abort a request if the middleware writer wants to. Middlewares *should* write to `ResponseWriter` if they *are* going to terminate the request, and they *should not* write to `ResponseWriter` if they *are not* going to terminate it.
+
+## Full Example
+
+Here's a complete, runnable example of a small `mux` based server:
+
+```go
+package main
+
+import (
+    "net/http"
+    "log"
+    "github.com/gorilla/mux"
+)
+
+func YourHandler(w http.ResponseWriter, r *http.Request) {
+    w.Write([]byte("Gorilla!\n"))
+}
+
+func main() {
+    r := mux.NewRouter()
+    // Routes consist of a path and a handler function.
+    r.HandleFunc("/", YourHandler)
+
+    // Bind to a port and pass our router in
+    log.Fatal(http.ListenAndServe(":8000", r))
+}
+```
+
+## License
+
+BSD licensed. See the LICENSE file for details.
diff --git a/vendor/github.com/gorilla/mux/context_gorilla.go b/vendor/github.com/gorilla/mux/context_gorilla.go
new file mode 100644
index 0000000..d7adaa8
--- /dev/null
+++ b/vendor/github.com/gorilla/mux/context_gorilla.go
@@ -0,0 +1,26 @@
+// +build !go1.7
+
+package mux
+
+import (
+	"net/http"
+
+	"github.com/gorilla/context"
+)
+
+func contextGet(r *http.Request, key interface{}) interface{} {
+	return context.Get(r, key)
+}
+
+func contextSet(r *http.Request, key, val interface{}) *http.Request {
+	if val == nil {
+		return r
+	}
+
+	context.Set(r, key, val)
+	return r
+}
+
+func contextClear(r *http.Request) {
+	context.Clear(r)
+}
diff --git a/vendor/github.com/gorilla/mux/context_native.go b/vendor/github.com/gorilla/mux/context_native.go
new file mode 100644
index 0000000..209cbea
--- /dev/null
+++ b/vendor/github.com/gorilla/mux/context_native.go
@@ -0,0 +1,24 @@
+// +build go1.7
+
+package mux
+
+import (
+	"context"
+	"net/http"
+)
+
+func contextGet(r *http.Request, key interface{}) interface{} {
+	return r.Context().Value(key)
+}
+
+func contextSet(r *http.Request, key, val interface{}) *http.Request {
+	if val == nil {
+		return r
+	}
+
+	return r.WithContext(context.WithValue(r.Context(), key, val))
+}
+
+func contextClear(r *http.Request) {
+	return
+}
diff --git a/vendor/github.com/gorilla/mux/doc.go b/vendor/github.com/gorilla/mux/doc.go
new file mode 100644
index 0000000..013f088
--- /dev/null
+++ b/vendor/github.com/gorilla/mux/doc.go
@@ -0,0 +1,307 @@
+// Copyright 2012 The Gorilla Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+Package mux implements a request router and dispatcher.
+
+The name mux stands for "HTTP request multiplexer". Like the standard
+http.ServeMux, mux.Router matches incoming requests against a list of
+registered routes and calls a handler for the route that matches the URL
+or other conditions. The main features are:
+
+	* Requests can be matched based on URL host, path, path prefix, schemes,
+	  header and query values, HTTP methods or using custom matchers.
+	* URL hosts, paths and query values can have variables with an optional
+	  regular expression.
+	* Registered URLs can be built, or "reversed", which helps maintaining
+	  references to resources.
+	* Routes can be used as subrouters: nested routes are only tested if the
+	  parent route matches. This is useful to define groups of routes that
+	  share common conditions like a host, a path prefix or other repeated
+	  attributes. As a bonus, this optimizes request matching.
+	* It implements the http.Handler interface so it is compatible with the
+	  standard http.ServeMux.
+
+Let's start registering a couple of URL paths and handlers:
+
+	func main() {
+		r := mux.NewRouter()
+		r.HandleFunc("/", HomeHandler)
+		r.HandleFunc("/products", ProductsHandler)
+		r.HandleFunc("/articles", ArticlesHandler)
+		http.Handle("/", r)
+	}
+
+Here we register three routes mapping URL paths to handlers. This is
+equivalent to how http.HandleFunc() works: if an incoming request URL matches
+one of the paths, the corresponding handler is called passing
+(http.ResponseWriter, *http.Request) as parameters.
+
+Paths can have variables. They are defined using the format {name} or
+{name:pattern}. If a regular expression pattern is not defined, the matched
+variable will be anything until the next slash. For example:
+
+	r := mux.NewRouter()
+	r.HandleFunc("/products/{key}", ProductHandler)
+	r.HandleFunc("/articles/{category}/", ArticlesCategoryHandler)
+	r.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler)
+
+Groups can be used inside patterns, as long as they are non-capturing (?:re). For example:
+
+	r.HandleFunc("/articles/{category}/{sort:(?:asc|desc|new)}", ArticlesCategoryHandler)
+
+The names are used to create a map of route variables which can be retrieved
+calling mux.Vars():
+
+	vars := mux.Vars(request)
+	category := vars["category"]
+
+Note that if any capturing groups are present, mux will panic() during parsing. To prevent
+this, convert any capturing groups to non-capturing, e.g. change "/{sort:(asc|desc)}" to
+"/{sort:(?:asc|desc)}". This is a change from prior versions which behaved unpredictably
+when capturing groups were present.
+
+And this is all you need to know about the basic usage. More advanced options
+are explained below.
+
+Routes can also be restricted to a domain or subdomain. Just define a host
+pattern to be matched. They can also have variables:
+
+	r := mux.NewRouter()
+	// Only matches if domain is "www.example.com".
+	r.Host("www.example.com")
+	// Matches a dynamic subdomain.
+	r.Host("{subdomain:[a-z]+}.domain.com")
+
+There are several other matchers that can be added. To match path prefixes:
+
+	r.PathPrefix("/products/")
+
+...or HTTP methods:
+
+	r.Methods("GET", "POST")
+
+...or URL schemes:
+
+	r.Schemes("https")
+
+...or header values:
+
+	r.Headers("X-Requested-With", "XMLHttpRequest")
+
+...or query values:
+
+	r.Queries("key", "value")
+
+...or to use a custom matcher function:
+
+	r.MatcherFunc(func(r *http.Request, rm *RouteMatch) bool {
+		return r.ProtoMajor == 0
+	})
+
+...and finally, it is possible to combine several matchers in a single route:
+
+	r.HandleFunc("/products", ProductsHandler).
+	  Host("www.example.com").
+	  Methods("GET").
+	  Schemes("http")
+
+Setting the same matching conditions again and again can be boring, so we have
+a way to group several routes that share the same requirements.
+We call it "subrouting".
+
+For example, let's say we have several URLs that should only match when the
+host is "www.example.com". Create a route for that host and get a "subrouter"
+from it:
+
+	r := mux.NewRouter()
+	s := r.Host("www.example.com").Subrouter()
+
+Then register routes in the subrouter:
+
+	s.HandleFunc("/products/", ProductsHandler)
+	s.HandleFunc("/products/{key}", ProductHandler)
+	s.HandleFunc("/articles/{category}/{id:[0-9]+}"), ArticleHandler)
+
+The three URL paths we registered above will only be tested if the domain is
+"www.example.com", because the subrouter is tested first. This is not
+only convenient, but also optimizes request matching. You can create
+subrouters combining any attribute matchers accepted by a route.
+
+Subrouters can be used to create domain or path "namespaces": you define
+subrouters in a central place and then parts of the app can register its
+paths relatively to a given subrouter.
+
+There's one more thing about subroutes. When a subrouter has a path prefix,
+the inner routes use it as base for their paths:
+
+	r := mux.NewRouter()
+	s := r.PathPrefix("/products").Subrouter()
+	// "/products/"
+	s.HandleFunc("/", ProductsHandler)
+	// "/products/{key}/"
+	s.HandleFunc("/{key}/", ProductHandler)
+	// "/products/{key}/details"
+	s.HandleFunc("/{key}/details", ProductDetailsHandler)
+
+Note that the path provided to PathPrefix() represents a "wildcard": calling
+PathPrefix("/static/").Handler(...) means that the handler will be passed any
+request that matches "/static/*". This makes it easy to serve static files with mux:
+
+	func main() {
+		var dir string
+
+		flag.StringVar(&dir, "dir", ".", "the directory to serve files from. Defaults to the current dir")
+		flag.Parse()
+		r := mux.NewRouter()
+
+		// This will serve files under http://localhost:8000/static/<filename>
+		r.PathPrefix("/static/").Handler(http.StripPrefix("/static/", http.FileServer(http.Dir(dir))))
+
+		srv := &http.Server{
+			Handler:      r,
+			Addr:         "127.0.0.1:8000",
+			// Good practice: enforce timeouts for servers you create!
+			WriteTimeout: 15 * time.Second,
+			ReadTimeout:  15 * time.Second,
+		}
+
+		log.Fatal(srv.ListenAndServe())
+	}
+
+Now let's see how to build registered URLs.
+
+Routes can be named. All routes that define a name can have their URLs built,
+or "reversed". We define a name calling Name() on a route. For example:
+
+	r := mux.NewRouter()
+	r.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler).
+	  Name("article")
+
+To build a URL, get the route and call the URL() method, passing a sequence of
+key/value pairs for the route variables. For the previous route, we would do:
+
+	url, err := r.Get("article").URL("category", "technology", "id", "42")
+
+...and the result will be a url.URL with the following path:
+
+	"/articles/technology/42"
+
+This also works for host and query value variables:
+
+	r := mux.NewRouter()
+	r.Host("{subdomain}.domain.com").
+	  Path("/articles/{category}/{id:[0-9]+}").
+	  Queries("filter", "{filter}").
+	  HandlerFunc(ArticleHandler).
+	  Name("article")
+
+	// url.String() will be "http://news.domain.com/articles/technology/42?filter=gorilla"
+	url, err := r.Get("article").URL("subdomain", "news",
+	                                 "category", "technology",
+	                                 "id", "42",
+	                                 "filter", "gorilla")
+
+All variables defined in the route are required, and their values must
+conform to the corresponding patterns. These requirements guarantee that a
+generated URL will always match a registered route -- the only exception is
+for explicitly defined "build-only" routes which never match.
+
+Regex support also exists for matching Headers within a route. For example, we could do:
+
+	r.HeadersRegexp("Content-Type", "application/(text|json)")
+
+...and the route will match both requests with a Content-Type of `application/json` as well as
+`application/text`
+
+There's also a way to build only the URL host or path for a route:
+use the methods URLHost() or URLPath() instead. For the previous route,
+we would do:
+
+	// "http://news.domain.com/"
+	host, err := r.Get("article").URLHost("subdomain", "news")
+
+	// "/articles/technology/42"
+	path, err := r.Get("article").URLPath("category", "technology", "id", "42")
+
+And if you use subrouters, host and path defined separately can be built
+as well:
+
+	r := mux.NewRouter()
+	s := r.Host("{subdomain}.domain.com").Subrouter()
+	s.Path("/articles/{category}/{id:[0-9]+}").
+	  HandlerFunc(ArticleHandler).
+	  Name("article")
+
+	// "http://news.domain.com/articles/technology/42"
+	url, err := r.Get("article").URL("subdomain", "news",
+	                                 "category", "technology",
+	                                 "id", "42")
+
+Since **vX.Y.Z**, mux supports the addition of middlewares to a [Router](https://godoc.org/github.com/gorilla/mux#Router), which are executed if a
+match is found (including subrouters). Middlewares are defined using the de facto standard type:
+
+	type MiddlewareFunc func(http.Handler) http.Handler
+
+Typically, the returned handler is a closure which does something with the http.ResponseWriter and http.Request passed to it, and then calls the handler passed as parameter to the MiddlewareFunc (closures can access variables from the context where they are created).
+
+A very basic middleware which logs the URI of the request being handled could be written as:
+
+	func simpleMw(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			// Do stuff here
+			log.Println(r.RequestURI)
+			// Call the next handler, which can be another middleware in the chain, or the final handler.
+			next.ServeHTTP(w, r)
+		})
+	}
+
+Middlewares can be added to a router using `Router.Use()`:
+
+	r := mux.NewRouter()
+	r.HandleFunc("/", handler)
+	r.AddMiddleware(simpleMw)
+
+A more complex authentication middleware, which maps session token to users, could be written as:
+
+	// Define our struct
+	type authenticationMiddleware struct {
+		tokenUsers map[string]string
+	}
+
+	// Initialize it somewhere
+	func (amw *authenticationMiddleware) Populate() {
+		amw.tokenUsers["00000000"] = "user0"
+		amw.tokenUsers["aaaaaaaa"] = "userA"
+		amw.tokenUsers["05f717e5"] = "randomUser"
+		amw.tokenUsers["deadbeef"] = "user0"
+	}
+
+	// Middleware function, which will be called for each request
+	func (amw *authenticationMiddleware) Middleware(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			token := r.Header.Get("X-Session-Token")
+
+			if user, found := amw.tokenUsers[token]; found {
+				// We found the token in our map
+				log.Printf("Authenticated user %s\n", user)
+				next.ServeHTTP(w, r)
+			} else {
+				http.Error(w, "Forbidden", 403)
+			}
+		})
+	}
+
+	r := mux.NewRouter()
+	r.HandleFunc("/", handler)
+
+	amw := authenticationMiddleware{}
+	amw.Populate()
+
+	r.Use(amw.Middleware)
+
+Note: The handler chain will be stopped if your middleware doesn't call `next.ServeHTTP()` with the corresponding parameters. This can be used to abort a request if the middleware writer wants to.
+
+*/
+package mux
diff --git a/vendor/github.com/gorilla/mux/middleware.go b/vendor/github.com/gorilla/mux/middleware.go
new file mode 100644
index 0000000..8f89867
--- /dev/null
+++ b/vendor/github.com/gorilla/mux/middleware.go
@@ -0,0 +1,28 @@
+package mux
+
+import "net/http"
+
+// MiddlewareFunc is a function which receives an http.Handler and returns another http.Handler.
+// Typically, the returned handler is a closure which does something with the http.ResponseWriter and http.Request passed
+// to it, and then calls the handler passed as parameter to the MiddlewareFunc.
+type MiddlewareFunc func(http.Handler) http.Handler
+
+// middleware interface is anything which implements a MiddlewareFunc named Middleware.
+type middleware interface {
+	Middleware(handler http.Handler) http.Handler
+}
+
+// MiddlewareFunc also implements the middleware interface.
+func (mw MiddlewareFunc) Middleware(handler http.Handler) http.Handler {
+	return mw(handler)
+}
+
+// Use appends a MiddlewareFunc to the chain. Middleware can be used to intercept or otherwise modify requests and/or responses, and are executed in the order that they are applied to the Router.
+func (r *Router) Use(mwf MiddlewareFunc) {
+	r.middlewares = append(r.middlewares, mwf)
+}
+
+// useInterface appends a middleware to the chain. Middleware can be used to intercept or otherwise modify requests and/or responses, and are executed in the order that they are applied to the Router.
+func (r *Router) useInterface(mw middleware) {
+	r.middlewares = append(r.middlewares, mw)
+}
diff --git a/vendor/github.com/gorilla/mux/mux.go b/vendor/github.com/gorilla/mux/mux.go
new file mode 100644
index 0000000..efabd24
--- /dev/null
+++ b/vendor/github.com/gorilla/mux/mux.go
@@ -0,0 +1,585 @@
+// Copyright 2012 The Gorilla Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mux
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+	"path"
+	"regexp"
+)
+
+var (
+	ErrMethodMismatch = errors.New("method is not allowed")
+	ErrNotFound       = errors.New("no matching route was found")
+)
+
+// NewRouter returns a new router instance.
+func NewRouter() *Router {
+	return &Router{namedRoutes: make(map[string]*Route), KeepContext: false}
+}
+
+// Router registers routes to be matched and dispatches a handler.
+//
+// It implements the http.Handler interface, so it can be registered to serve
+// requests:
+//
+//     var router = mux.NewRouter()
+//
+//     func main() {
+//         http.Handle("/", router)
+//     }
+//
+// Or, for Google App Engine, register it in a init() function:
+//
+//     func init() {
+//         http.Handle("/", router)
+//     }
+//
+// This will send all incoming requests to the router.
+type Router struct {
+	// Configurable Handler to be used when no route matches.
+	NotFoundHandler http.Handler
+
+	// Configurable Handler to be used when the request method does not match the route.
+	MethodNotAllowedHandler http.Handler
+
+	// Parent route, if this is a subrouter.
+	parent parentRoute
+	// Routes to be matched, in order.
+	routes []*Route
+	// Routes by name for URL building.
+	namedRoutes map[string]*Route
+	// See Router.StrictSlash(). This defines the flag for new routes.
+	strictSlash bool
+	// See Router.SkipClean(). This defines the flag for new routes.
+	skipClean bool
+	// If true, do not clear the request context after handling the request.
+	// This has no effect when go1.7+ is used, since the context is stored
+	// on the request itself.
+	KeepContext bool
+	// see Router.UseEncodedPath(). This defines a flag for all routes.
+	useEncodedPath bool
+	// Slice of middlewares to be called after a match is found
+	middlewares []middleware
+}
+
+// Match attempts to match the given request against the router's registered routes.
+//
+// If the request matches a route of this router or one of its subrouters the Route,
+// Handler, and Vars fields of the the match argument are filled and this function
+// returns true.
+//
+// If the request does not match any of this router's or its subrouters' routes
+// then this function returns false. If available, a reason for the match failure
+// will be filled in the match argument's MatchErr field. If the match failure type
+// (eg: not found) has a registered handler, the handler is assigned to the Handler
+// field of the match argument.
+func (r *Router) Match(req *http.Request, match *RouteMatch) bool {
+	for _, route := range r.routes {
+		if route.Match(req, match) {
+			// Build middleware chain if no error was found
+			if match.MatchErr == nil {
+				for i := len(r.middlewares) - 1; i >= 0; i-- {
+					match.Handler = r.middlewares[i].Middleware(match.Handler)
+				}
+			}
+			return true
+		}
+	}
+
+	if match.MatchErr == ErrMethodMismatch {
+		if r.MethodNotAllowedHandler != nil {
+			match.Handler = r.MethodNotAllowedHandler
+			return true
+		} else {
+			return false
+		}
+	}
+
+	// Closest match for a router (includes sub-routers)
+	if r.NotFoundHandler != nil {
+		match.Handler = r.NotFoundHandler
+		match.MatchErr = ErrNotFound
+		return true
+	}
+
+	match.MatchErr = ErrNotFound
+	return false
+}
+
+// ServeHTTP dispatches the handler registered in the matched route.
+//
+// When there is a match, the route variables can be retrieved calling
+// mux.Vars(request).
+func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	if !r.skipClean {
+		path := req.URL.Path
+		if r.useEncodedPath {
+			path = req.URL.EscapedPath()
+		}
+		// Clean path to canonical form and redirect.
+		if p := cleanPath(path); p != path {
+
+			// Added 3 lines (Philip Schlump) - It was dropping the query string and #whatever from query.
+			// This matches with fix in go 1.2 r.c. 4 for same problem.  Go Issue:
+			// http://code.google.com/p/go/issues/detail?id=5252
+			url := *req.URL
+			url.Path = p
+			p = url.String()
+
+			w.Header().Set("Location", p)
+			w.WriteHeader(http.StatusMovedPermanently)
+			return
+		}
+	}
+	var match RouteMatch
+	var handler http.Handler
+	if r.Match(req, &match) {
+		handler = match.Handler
+		req = setVars(req, match.Vars)
+		req = setCurrentRoute(req, match.Route)
+	}
+
+	if handler == nil && match.MatchErr == ErrMethodMismatch {
+		handler = methodNotAllowedHandler()
+	}
+
+	if handler == nil {
+		handler = http.NotFoundHandler()
+	}
+
+	if !r.KeepContext {
+		defer contextClear(req)
+	}
+
+	handler.ServeHTTP(w, req)
+}
+
+// Get returns a route registered with the given name.
+func (r *Router) Get(name string) *Route {
+	return r.getNamedRoutes()[name]
+}
+
+// GetRoute returns a route registered with the given name. This method
+// was renamed to Get() and remains here for backwards compatibility.
+func (r *Router) GetRoute(name string) *Route {
+	return r.getNamedRoutes()[name]
+}
+
+// StrictSlash defines the trailing slash behavior for new routes. The initial
+// value is false.
+//
+// When true, if the route path is "/path/", accessing "/path" will perform a redirect
+// to the former and vice versa. In other words, your application will always
+// see the path as specified in the route.
+//
+// When false, if the route path is "/path", accessing "/path/" will not match
+// this route and vice versa.
+//
+// The re-direct is a HTTP 301 (Moved Permanently). Note that when this is set for
+// routes with a non-idempotent method (e.g. POST, PUT), the subsequent re-directed
+// request will be made as a GET by most clients. Use middleware or client settings
+// to modify this behaviour as needed.
+//
+// Special case: when a route sets a path prefix using the PathPrefix() method,
+// strict slash is ignored for that route because the redirect behavior can't
+// be determined from a prefix alone. However, any subrouters created from that
+// route inherit the original StrictSlash setting.
+func (r *Router) StrictSlash(value bool) *Router {
+	r.strictSlash = value
+	return r
+}
+
+// SkipClean defines the path cleaning behaviour for new routes. The initial
+// value is false. Users should be careful about which routes are not cleaned
+//
+// When true, if the route path is "/path//to", it will remain with the double
+// slash. This is helpful if you have a route like: /fetch/http://xkcd.com/534/
+//
+// When false, the path will be cleaned, so /fetch/http://xkcd.com/534/ will
+// become /fetch/http/xkcd.com/534
+func (r *Router) SkipClean(value bool) *Router {
+	r.skipClean = value
+	return r
+}
+
+// UseEncodedPath tells the router to match the encoded original path
+// to the routes.
+// For eg. "/path/foo%2Fbar/to" will match the path "/path/{var}/to".
+//
+// If not called, the router will match the unencoded path to the routes.
+// For eg. "/path/foo%2Fbar/to" will match the path "/path/foo/bar/to"
+func (r *Router) UseEncodedPath() *Router {
+	r.useEncodedPath = true
+	return r
+}
+
+// ----------------------------------------------------------------------------
+// parentRoute
+// ----------------------------------------------------------------------------
+
+func (r *Router) getBuildScheme() string {
+	if r.parent != nil {
+		return r.parent.getBuildScheme()
+	}
+	return ""
+}
+
+// getNamedRoutes returns the map where named routes are registered.
+func (r *Router) getNamedRoutes() map[string]*Route {
+	if r.namedRoutes == nil {
+		if r.parent != nil {
+			r.namedRoutes = r.parent.getNamedRoutes()
+		} else {
+			r.namedRoutes = make(map[string]*Route)
+		}
+	}
+	return r.namedRoutes
+}
+
+// getRegexpGroup returns regexp definitions from the parent route, if any.
+func (r *Router) getRegexpGroup() *routeRegexpGroup {
+	if r.parent != nil {
+		return r.parent.getRegexpGroup()
+	}
+	return nil
+}
+
+func (r *Router) buildVars(m map[string]string) map[string]string {
+	if r.parent != nil {
+		m = r.parent.buildVars(m)
+	}
+	return m
+}
+
+// ----------------------------------------------------------------------------
+// Route factories
+// ----------------------------------------------------------------------------
+
+// NewRoute registers an empty route.
+func (r *Router) NewRoute() *Route {
+	route := &Route{parent: r, strictSlash: r.strictSlash, skipClean: r.skipClean, useEncodedPath: r.useEncodedPath}
+	r.routes = append(r.routes, route)
+	return route
+}
+
+// Handle registers a new route with a matcher for the URL path.
+// See Route.Path() and Route.Handler().
+func (r *Router) Handle(path string, handler http.Handler) *Route {
+	return r.NewRoute().Path(path).Handler(handler)
+}
+
+// HandleFunc registers a new route with a matcher for the URL path.
+// See Route.Path() and Route.HandlerFunc().
+func (r *Router) HandleFunc(path string, f func(http.ResponseWriter,
+	*http.Request)) *Route {
+	return r.NewRoute().Path(path).HandlerFunc(f)
+}
+
+// Headers registers a new route with a matcher for request header values.
+// See Route.Headers().
+func (r *Router) Headers(pairs ...string) *Route {
+	return r.NewRoute().Headers(pairs...)
+}
+
+// Host registers a new route with a matcher for the URL host.
+// See Route.Host().
+func (r *Router) Host(tpl string) *Route {
+	return r.NewRoute().Host(tpl)
+}
+
+// MatcherFunc registers a new route with a custom matcher function.
+// See Route.MatcherFunc().
+func (r *Router) MatcherFunc(f MatcherFunc) *Route {
+	return r.NewRoute().MatcherFunc(f)
+}
+
+// Methods registers a new route with a matcher for HTTP methods.
+// See Route.Methods().
+func (r *Router) Methods(methods ...string) *Route {
+	return r.NewRoute().Methods(methods...)
+}
+
+// Path registers a new route with a matcher for the URL path.
+// See Route.Path().
+func (r *Router) Path(tpl string) *Route {
+	return r.NewRoute().Path(tpl)
+}
+
+// PathPrefix registers a new route with a matcher for the URL path prefix.
+// See Route.PathPrefix().
+func (r *Router) PathPrefix(tpl string) *Route {
+	return r.NewRoute().PathPrefix(tpl)
+}
+
+// Queries registers a new route with a matcher for URL query values.
+// See Route.Queries().
+func (r *Router) Queries(pairs ...string) *Route {
+	return r.NewRoute().Queries(pairs...)
+}
+
+// Schemes registers a new route with a matcher for URL schemes.
+// See Route.Schemes().
+func (r *Router) Schemes(schemes ...string) *Route {
+	return r.NewRoute().Schemes(schemes...)
+}
+
+// BuildVarsFunc registers a new route with a custom function for modifying
+// route variables before building a URL.
+func (r *Router) BuildVarsFunc(f BuildVarsFunc) *Route {
+	return r.NewRoute().BuildVarsFunc(f)
+}
+
+// Walk walks the router and all its sub-routers, calling walkFn for each route
+// in the tree. The routes are walked in the order they were added. Sub-routers
+// are explored depth-first.
+func (r *Router) Walk(walkFn WalkFunc) error {
+	return r.walk(walkFn, []*Route{})
+}
+
+// SkipRouter is used as a return value from WalkFuncs to indicate that the
+// router that walk is about to descend down to should be skipped.
+var SkipRouter = errors.New("skip this router")
+
+// WalkFunc is the type of the function called for each route visited by Walk.
+// At every invocation, it is given the current route, and the current router,
+// and a list of ancestor routes that lead to the current route.
+type WalkFunc func(route *Route, router *Router, ancestors []*Route) error
+
+func (r *Router) walk(walkFn WalkFunc, ancestors []*Route) error {
+	for _, t := range r.routes {
+		err := walkFn(t, r, ancestors)
+		if err == SkipRouter {
+			continue
+		}
+		if err != nil {
+			return err
+		}
+		for _, sr := range t.matchers {
+			if h, ok := sr.(*Router); ok {
+				ancestors = append(ancestors, t)
+				err := h.walk(walkFn, ancestors)
+				if err != nil {
+					return err
+				}
+				ancestors = ancestors[:len(ancestors)-1]
+			}
+		}
+		if h, ok := t.handler.(*Router); ok {
+			ancestors = append(ancestors, t)
+			err := h.walk(walkFn, ancestors)
+			if err != nil {
+				return err
+			}
+			ancestors = ancestors[:len(ancestors)-1]
+		}
+	}
+	return nil
+}
+
+// ----------------------------------------------------------------------------
+// Context
+// ----------------------------------------------------------------------------
+
+// RouteMatch stores information about a matched route.
+type RouteMatch struct {
+	Route   *Route
+	Handler http.Handler
+	Vars    map[string]string
+
+	// MatchErr is set to appropriate matching error
+	// It is set to ErrMethodMismatch if there is a mismatch in
+	// the request method and route method
+	MatchErr error
+}
+
+type contextKey int
+
+const (
+	varsKey contextKey = iota
+	routeKey
+)
+
+// Vars returns the route variables for the current request, if any.
+func Vars(r *http.Request) map[string]string {
+	if rv := contextGet(r, varsKey); rv != nil {
+		return rv.(map[string]string)
+	}
+	return nil
+}
+
+// CurrentRoute returns the matched route for the current request, if any.
+// This only works when called inside the handler of the matched route
+// because the matched route is stored in the request context which is cleared
+// after the handler returns, unless the KeepContext option is set on the
+// Router.
+func CurrentRoute(r *http.Request) *Route {
+	if rv := contextGet(r, routeKey); rv != nil {
+		return rv.(*Route)
+	}
+	return nil
+}
+
+func setVars(r *http.Request, val interface{}) *http.Request {
+	return contextSet(r, varsKey, val)
+}
+
+func setCurrentRoute(r *http.Request, val interface{}) *http.Request {
+	return contextSet(r, routeKey, val)
+}
+
+// ----------------------------------------------------------------------------
+// Helpers
+// ----------------------------------------------------------------------------
+
+// cleanPath returns the canonical path for p, eliminating . and .. elements.
+// Borrowed from the net/http package.
+func cleanPath(p string) string {
+	if p == "" {
+		return "/"
+	}
+	if p[0] != '/' {
+		p = "/" + p
+	}
+	np := path.Clean(p)
+	// path.Clean removes trailing slash except for root;
+	// put the trailing slash back if necessary.
+	if p[len(p)-1] == '/' && np != "/" {
+		np += "/"
+	}
+
+	return np
+}
+
+// uniqueVars returns an error if two slices contain duplicated strings.
+func uniqueVars(s1, s2 []string) error {
+	for _, v1 := range s1 {
+		for _, v2 := range s2 {
+			if v1 == v2 {
+				return fmt.Errorf("mux: duplicated route variable %q", v2)
+			}
+		}
+	}
+	return nil
+}
+
+// checkPairs returns the count of strings passed in, and an error if
+// the count is not an even number.
+func checkPairs(pairs ...string) (int, error) {
+	length := len(pairs)
+	if length%2 != 0 {
+		return length, fmt.Errorf(
+			"mux: number of parameters must be multiple of 2, got %v", pairs)
+	}
+	return length, nil
+}
+
+// mapFromPairsToString converts variadic string parameters to a
+// string to string map.
+func mapFromPairsToString(pairs ...string) (map[string]string, error) {
+	length, err := checkPairs(pairs...)
+	if err != nil {
+		return nil, err
+	}
+	m := make(map[string]string, length/2)
+	for i := 0; i < length; i += 2 {
+		m[pairs[i]] = pairs[i+1]
+	}
+	return m, nil
+}
+
+// mapFromPairsToRegex converts variadic string parameters to a
+// string to regex map.
+func mapFromPairsToRegex(pairs ...string) (map[string]*regexp.Regexp, error) {
+	length, err := checkPairs(pairs...)
+	if err != nil {
+		return nil, err
+	}
+	m := make(map[string]*regexp.Regexp, length/2)
+	for i := 0; i < length; i += 2 {
+		regex, err := regexp.Compile(pairs[i+1])
+		if err != nil {
+			return nil, err
+		}
+		m[pairs[i]] = regex
+	}
+	return m, nil
+}
+
+// matchInArray returns true if the given string value is in the array.
+func matchInArray(arr []string, value string) bool {
+	for _, v := range arr {
+		if v == value {
+			return true
+		}
+	}
+	return false
+}
+
+// matchMapWithString returns true if the given key/value pairs exist in a given map.
+func matchMapWithString(toCheck map[string]string, toMatch map[string][]string, canonicalKey bool) bool {
+	for k, v := range toCheck {
+		// Check if key exists.
+		if canonicalKey {
+			k = http.CanonicalHeaderKey(k)
+		}
+		if values := toMatch[k]; values == nil {
+			return false
+		} else if v != "" {
+			// If value was defined as an empty string we only check that the
+			// key exists. Otherwise we also check for equality.
+			valueExists := false
+			for _, value := range values {
+				if v == value {
+					valueExists = true
+					break
+				}
+			}
+			if !valueExists {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// matchMapWithRegex returns true if the given key/value pairs exist in a given map compiled against
+// the given regex
+func matchMapWithRegex(toCheck map[string]*regexp.Regexp, toMatch map[string][]string, canonicalKey bool) bool {
+	for k, v := range toCheck {
+		// Check if key exists.
+		if canonicalKey {
+			k = http.CanonicalHeaderKey(k)
+		}
+		if values := toMatch[k]; values == nil {
+			return false
+		} else if v != nil {
+			// If value was defined as an empty string we only check that the
+			// key exists. Otherwise we also check for equality.
+			valueExists := false
+			for _, value := range values {
+				if v.MatchString(value) {
+					valueExists = true
+					break
+				}
+			}
+			if !valueExists {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// methodNotAllowed replies to the request with an HTTP status code 405.
+func methodNotAllowed(w http.ResponseWriter, r *http.Request) {
+	w.WriteHeader(http.StatusMethodNotAllowed)
+}
+
+// methodNotAllowedHandler returns a simple request handler
+// that replies to each request with a status code 405.
+func methodNotAllowedHandler() http.Handler { return http.HandlerFunc(methodNotAllowed) }
diff --git a/vendor/github.com/gorilla/mux/regexp.go b/vendor/github.com/gorilla/mux/regexp.go
new file mode 100644
index 0000000..2b57e56
--- /dev/null
+++ b/vendor/github.com/gorilla/mux/regexp.go
@@ -0,0 +1,332 @@
+// Copyright 2012 The Gorilla Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mux
+
+import (
+	"bytes"
+	"fmt"
+	"net/http"
+	"net/url"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+type routeRegexpOptions struct {
+	strictSlash    bool
+	useEncodedPath bool
+}
+
+type regexpType int
+
+const (
+	regexpTypePath   regexpType = 0
+	regexpTypeHost   regexpType = 1
+	regexpTypePrefix regexpType = 2
+	regexpTypeQuery  regexpType = 3
+)
+
+// newRouteRegexp parses a route template and returns a routeRegexp,
+// used to match a host, a path or a query string.
+//
+// It will extract named variables, assemble a regexp to be matched, create
+// a "reverse" template to build URLs and compile regexps to validate variable
+// values used in URL building.
+//
+// Previously we accepted only Python-like identifiers for variable
+// names ([a-zA-Z_][a-zA-Z0-9_]*), but currently the only restriction is that
+// name and pattern can't be empty, and names can't contain a colon.
+func newRouteRegexp(tpl string, typ regexpType, options routeRegexpOptions) (*routeRegexp, error) {
+	// Check if it is well-formed.
+	idxs, errBraces := braceIndices(tpl)
+	if errBraces != nil {
+		return nil, errBraces
+	}
+	// Backup the original.
+	template := tpl
+	// Now let's parse it.
+	defaultPattern := "[^/]+"
+	if typ == regexpTypeQuery {
+		defaultPattern = ".*"
+	} else if typ == regexpTypeHost {
+		defaultPattern = "[^.]+"
+	}
+	// Only match strict slash if not matching
+	if typ != regexpTypePath {
+		options.strictSlash = false
+	}
+	// Set a flag for strictSlash.
+	endSlash := false
+	if options.strictSlash && strings.HasSuffix(tpl, "/") {
+		tpl = tpl[:len(tpl)-1]
+		endSlash = true
+	}
+	varsN := make([]string, len(idxs)/2)
+	varsR := make([]*regexp.Regexp, len(idxs)/2)
+	pattern := bytes.NewBufferString("")
+	pattern.WriteByte('^')
+	reverse := bytes.NewBufferString("")
+	var end int
+	var err error
+	for i := 0; i < len(idxs); i += 2 {
+		// Set all values we are interested in.
+		raw := tpl[end:idxs[i]]
+		end = idxs[i+1]
+		parts := strings.SplitN(tpl[idxs[i]+1:end-1], ":", 2)
+		name := parts[0]
+		patt := defaultPattern
+		if len(parts) == 2 {
+			patt = parts[1]
+		}
+		// Name or pattern can't be empty.
+		if name == "" || patt == "" {
+			return nil, fmt.Errorf("mux: missing name or pattern in %q",
+				tpl[idxs[i]:end])
+		}
+		// Build the regexp pattern.
+		fmt.Fprintf(pattern, "%s(?P<%s>%s)", regexp.QuoteMeta(raw), varGroupName(i/2), patt)
+
+		// Build the reverse template.
+		fmt.Fprintf(reverse, "%s%%s", raw)
+
+		// Append variable name and compiled pattern.
+		varsN[i/2] = name
+		varsR[i/2], err = regexp.Compile(fmt.Sprintf("^%s$", patt))
+		if err != nil {
+			return nil, err
+		}
+	}
+	// Add the remaining.
+	raw := tpl[end:]
+	pattern.WriteString(regexp.QuoteMeta(raw))
+	if options.strictSlash {
+		pattern.WriteString("[/]?")
+	}
+	if typ == regexpTypeQuery {
+		// Add the default pattern if the query value is empty
+		if queryVal := strings.SplitN(template, "=", 2)[1]; queryVal == "" {
+			pattern.WriteString(defaultPattern)
+		}
+	}
+	if typ != regexpTypePrefix {
+		pattern.WriteByte('$')
+	}
+	reverse.WriteString(raw)
+	if endSlash {
+		reverse.WriteByte('/')
+	}
+	// Compile full regexp.
+	reg, errCompile := regexp.Compile(pattern.String())
+	if errCompile != nil {
+		return nil, errCompile
+	}
+
+	// Check for capturing groups which used to work in older versions
+	if reg.NumSubexp() != len(idxs)/2 {
+		panic(fmt.Sprintf("route %s contains capture groups in its regexp. ", template) +
+			"Only non-capturing groups are accepted: e.g. (?:pattern) instead of (pattern)")
+	}
+
+	// Done!
+	return &routeRegexp{
+		template:   template,
+		regexpType: typ,
+		options:    options,
+		regexp:     reg,
+		reverse:    reverse.String(),
+		varsN:      varsN,
+		varsR:      varsR,
+	}, nil
+}
+
+// routeRegexp stores a regexp to match a host or path and information to
+// collect and validate route variables.
+type routeRegexp struct {
+	// The unmodified template.
+	template string
+	// The type of match
+	regexpType regexpType
+	// Options for matching
+	options routeRegexpOptions
+	// Expanded regexp.
+	regexp *regexp.Regexp
+	// Reverse template.
+	reverse string
+	// Variable names.
+	varsN []string
+	// Variable regexps (validators).
+	varsR []*regexp.Regexp
+}
+
+// Match matches the regexp against the URL host or path.
+func (r *routeRegexp) Match(req *http.Request, match *RouteMatch) bool {
+	if r.regexpType != regexpTypeHost {
+		if r.regexpType == regexpTypeQuery {
+			return r.matchQueryString(req)
+		}
+		path := req.URL.Path
+		if r.options.useEncodedPath {
+			path = req.URL.EscapedPath()
+		}
+		return r.regexp.MatchString(path)
+	}
+
+	return r.regexp.MatchString(getHost(req))
+}
+
+// url builds a URL part using the given values.
+func (r *routeRegexp) url(values map[string]string) (string, error) {
+	urlValues := make([]interface{}, len(r.varsN))
+	for k, v := range r.varsN {
+		value, ok := values[v]
+		if !ok {
+			return "", fmt.Errorf("mux: missing route variable %q", v)
+		}
+		if r.regexpType == regexpTypeQuery {
+			value = url.QueryEscape(value)
+		}
+		urlValues[k] = value
+	}
+	rv := fmt.Sprintf(r.reverse, urlValues...)
+	if !r.regexp.MatchString(rv) {
+		// The URL is checked against the full regexp, instead of checking
+		// individual variables. This is faster but to provide a good error
+		// message, we check individual regexps if the URL doesn't match.
+		for k, v := range r.varsN {
+			if !r.varsR[k].MatchString(values[v]) {
+				return "", fmt.Errorf(
+					"mux: variable %q doesn't match, expected %q", values[v],
+					r.varsR[k].String())
+			}
+		}
+	}
+	return rv, nil
+}
+
+// getURLQuery returns a single query parameter from a request URL.
+// For a URL with foo=bar&baz=ding, we return only the relevant key
+// value pair for the routeRegexp.
+func (r *routeRegexp) getURLQuery(req *http.Request) string {
+	if r.regexpType != regexpTypeQuery {
+		return ""
+	}
+	templateKey := strings.SplitN(r.template, "=", 2)[0]
+	for key, vals := range req.URL.Query() {
+		if key == templateKey && len(vals) > 0 {
+			return key + "=" + vals[0]
+		}
+	}
+	return ""
+}
+
+func (r *routeRegexp) matchQueryString(req *http.Request) bool {
+	return r.regexp.MatchString(r.getURLQuery(req))
+}
+
+// braceIndices returns the first level curly brace indices from a string.
+// It returns an error in case of unbalanced braces.
+func braceIndices(s string) ([]int, error) {
+	var level, idx int
+	var idxs []int
+	for i := 0; i < len(s); i++ {
+		switch s[i] {
+		case '{':
+			if level++; level == 1 {
+				idx = i
+			}
+		case '}':
+			if level--; level == 0 {
+				idxs = append(idxs, idx, i+1)
+			} else if level < 0 {
+				return nil, fmt.Errorf("mux: unbalanced braces in %q", s)
+			}
+		}
+	}
+	if level != 0 {
+		return nil, fmt.Errorf("mux: unbalanced braces in %q", s)
+	}
+	return idxs, nil
+}
+
+// varGroupName builds a capturing group name for the indexed variable.
+func varGroupName(idx int) string {
+	return "v" + strconv.Itoa(idx)
+}
+
+// ----------------------------------------------------------------------------
+// routeRegexpGroup
+// ----------------------------------------------------------------------------
+
+// routeRegexpGroup groups the route matchers that carry variables.
+type routeRegexpGroup struct {
+	host    *routeRegexp
+	path    *routeRegexp
+	queries []*routeRegexp
+}
+
+// setMatch extracts the variables from the URL once a route matches.
+func (v *routeRegexpGroup) setMatch(req *http.Request, m *RouteMatch, r *Route) {
+	// Store host variables.
+	if v.host != nil {
+		host := getHost(req)
+		matches := v.host.regexp.FindStringSubmatchIndex(host)
+		if len(matches) > 0 {
+			extractVars(host, matches, v.host.varsN, m.Vars)
+		}
+	}
+	path := req.URL.Path
+	if r.useEncodedPath {
+		path = req.URL.EscapedPath()
+	}
+	// Store path variables.
+	if v.path != nil {
+		matches := v.path.regexp.FindStringSubmatchIndex(path)
+		if len(matches) > 0 {
+			extractVars(path, matches, v.path.varsN, m.Vars)
+			// Check if we should redirect.
+			if v.path.options.strictSlash {
+				p1 := strings.HasSuffix(path, "/")
+				p2 := strings.HasSuffix(v.path.template, "/")
+				if p1 != p2 {
+					u, _ := url.Parse(req.URL.String())
+					if p1 {
+						u.Path = u.Path[:len(u.Path)-1]
+					} else {
+						u.Path += "/"
+					}
+					m.Handler = http.RedirectHandler(u.String(), 301)
+				}
+			}
+		}
+	}
+	// Store query string variables.
+	for _, q := range v.queries {
+		queryURL := q.getURLQuery(req)
+		matches := q.regexp.FindStringSubmatchIndex(queryURL)
+		if len(matches) > 0 {
+			extractVars(queryURL, matches, q.varsN, m.Vars)
+		}
+	}
+}
+
+// getHost tries its best to return the request host.
+func getHost(r *http.Request) string {
+	if r.URL.IsAbs() {
+		return r.URL.Host
+	}
+	host := r.Host
+	// Slice off any port information.
+	if i := strings.Index(host, ":"); i != -1 {
+		host = host[:i]
+	}
+	return host
+
+}
+
+func extractVars(input string, matches []int, names []string, output map[string]string) {
+	for i, name := range names {
+		output[name] = input[matches[2*i+2]:matches[2*i+3]]
+	}
+}
diff --git a/vendor/github.com/gorilla/mux/route.go b/vendor/github.com/gorilla/mux/route.go
new file mode 100644
index 0000000..4ce098d
--- /dev/null
+++ b/vendor/github.com/gorilla/mux/route.go
@@ -0,0 +1,761 @@
+// Copyright 2012 The Gorilla Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mux
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+	"net/url"
+	"regexp"
+	"strings"
+)
+
+// Route stores information to match a request and build URLs.
+type Route struct {
+	// Parent where the route was registered (a Router).
+	parent parentRoute
+	// Request handler for the route.
+	handler http.Handler
+	// List of matchers.
+	matchers []matcher
+	// Manager for the variables from host and path.
+	regexp *routeRegexpGroup
+	// If true, when the path pattern is "/path/", accessing "/path" will
+	// redirect to the former and vice versa.
+	strictSlash bool
+	// If true, when the path pattern is "/path//to", accessing "/path//to"
+	// will not redirect
+	skipClean bool
+	// If true, "/path/foo%2Fbar/to" will match the path "/path/{var}/to"
+	useEncodedPath bool
+	// The scheme used when building URLs.
+	buildScheme string
+	// If true, this route never matches: it is only used to build URLs.
+	buildOnly bool
+	// The name used to build URLs.
+	name string
+	// Error resulted from building a route.
+	err error
+
+	buildVarsFunc BuildVarsFunc
+}
+
+func (r *Route) SkipClean() bool {
+	return r.skipClean
+}
+
+// Match matches the route against the request.
+func (r *Route) Match(req *http.Request, match *RouteMatch) bool {
+	if r.buildOnly || r.err != nil {
+		return false
+	}
+
+	var matchErr error
+
+	// Match everything.
+	for _, m := range r.matchers {
+		if matched := m.Match(req, match); !matched {
+			if _, ok := m.(methodMatcher); ok {
+				matchErr = ErrMethodMismatch
+				continue
+			}
+			matchErr = nil
+			return false
+		}
+	}
+
+	if matchErr != nil {
+		match.MatchErr = matchErr
+		return false
+	}
+
+	if match.MatchErr == ErrMethodMismatch {
+		// We found a route which matches request method, clear MatchErr
+		match.MatchErr = nil
+		// Then override the mis-matched handler
+		match.Handler = r.handler
+	}
+
+	// Yay, we have a match. Let's collect some info about it.
+	if match.Route == nil {
+		match.Route = r
+	}
+	if match.Handler == nil {
+		match.Handler = r.handler
+	}
+	if match.Vars == nil {
+		match.Vars = make(map[string]string)
+	}
+
+	// Set variables.
+	if r.regexp != nil {
+		r.regexp.setMatch(req, match, r)
+	}
+	return true
+}
+
+// ----------------------------------------------------------------------------
+// Route attributes
+// ----------------------------------------------------------------------------
+
+// GetError returns an error resulted from building the route, if any.
+func (r *Route) GetError() error {
+	return r.err
+}
+
+// BuildOnly sets the route to never match: it is only used to build URLs.
+func (r *Route) BuildOnly() *Route {
+	r.buildOnly = true
+	return r
+}
+
+// Handler --------------------------------------------------------------------
+
+// Handler sets a handler for the route.
+func (r *Route) Handler(handler http.Handler) *Route {
+	if r.err == nil {
+		r.handler = handler
+	}
+	return r
+}
+
+// HandlerFunc sets a handler function for the route.
+func (r *Route) HandlerFunc(f func(http.ResponseWriter, *http.Request)) *Route {
+	return r.Handler(http.HandlerFunc(f))
+}
+
+// GetHandler returns the handler for the route, if any.
+func (r *Route) GetHandler() http.Handler {
+	return r.handler
+}
+
+// Name -----------------------------------------------------------------------
+
+// Name sets the name for the route, used to build URLs.
+// If the name was registered already it will be overwritten.
+func (r *Route) Name(name string) *Route {
+	if r.name != "" {
+		r.err = fmt.Errorf("mux: route already has name %q, can't set %q",
+			r.name, name)
+	}
+	if r.err == nil {
+		r.name = name
+		r.getNamedRoutes()[name] = r
+	}
+	return r
+}
+
+// GetName returns the name for the route, if any.
+func (r *Route) GetName() string {
+	return r.name
+}
+
+// ----------------------------------------------------------------------------
+// Matchers
+// ----------------------------------------------------------------------------
+
+// matcher types try to match a request.
+type matcher interface {
+	Match(*http.Request, *RouteMatch) bool
+}
+
+// addMatcher adds a matcher to the route.
+func (r *Route) addMatcher(m matcher) *Route {
+	if r.err == nil {
+		r.matchers = append(r.matchers, m)
+	}
+	return r
+}
+
+// addRegexpMatcher adds a host or path matcher and builder to a route.
+func (r *Route) addRegexpMatcher(tpl string, typ regexpType) error {
+	if r.err != nil {
+		return r.err
+	}
+	r.regexp = r.getRegexpGroup()
+	if typ == regexpTypePath || typ == regexpTypePrefix {
+		if len(tpl) > 0 && tpl[0] != '/' {
+			return fmt.Errorf("mux: path must start with a slash, got %q", tpl)
+		}
+		if r.regexp.path != nil {
+			tpl = strings.TrimRight(r.regexp.path.template, "/") + tpl
+		}
+	}
+	rr, err := newRouteRegexp(tpl, typ, routeRegexpOptions{
+		strictSlash:    r.strictSlash,
+		useEncodedPath: r.useEncodedPath,
+	})
+	if err != nil {
+		return err
+	}
+	for _, q := range r.regexp.queries {
+		if err = uniqueVars(rr.varsN, q.varsN); err != nil {
+			return err
+		}
+	}
+	if typ == regexpTypeHost {
+		if r.regexp.path != nil {
+			if err = uniqueVars(rr.varsN, r.regexp.path.varsN); err != nil {
+				return err
+			}
+		}
+		r.regexp.host = rr
+	} else {
+		if r.regexp.host != nil {
+			if err = uniqueVars(rr.varsN, r.regexp.host.varsN); err != nil {
+				return err
+			}
+		}
+		if typ == regexpTypeQuery {
+			r.regexp.queries = append(r.regexp.queries, rr)
+		} else {
+			r.regexp.path = rr
+		}
+	}
+	r.addMatcher(rr)
+	return nil
+}
+
+// Headers --------------------------------------------------------------------
+
+// headerMatcher matches the request against header values.
+type headerMatcher map[string]string
+
+func (m headerMatcher) Match(r *http.Request, match *RouteMatch) bool {
+	return matchMapWithString(m, r.Header, true)
+}
+
+// Headers adds a matcher for request header values.
+// It accepts a sequence of key/value pairs to be matched. For example:
+//
+//     r := mux.NewRouter()
+//     r.Headers("Content-Type", "application/json",
+//               "X-Requested-With", "XMLHttpRequest")
+//
+// The above route will only match if both request header values match.
+// If the value is an empty string, it will match any value if the key is set.
+func (r *Route) Headers(pairs ...string) *Route {
+	if r.err == nil {
+		var headers map[string]string
+		headers, r.err = mapFromPairsToString(pairs...)
+		return r.addMatcher(headerMatcher(headers))
+	}
+	return r
+}
+
+// headerRegexMatcher matches the request against the route given a regex for the header
+type headerRegexMatcher map[string]*regexp.Regexp
+
+func (m headerRegexMatcher) Match(r *http.Request, match *RouteMatch) bool {
+	return matchMapWithRegex(m, r.Header, true)
+}
+
+// HeadersRegexp accepts a sequence of key/value pairs, where the value has regex
+// support. For example:
+//
+//     r := mux.NewRouter()
+//     r.HeadersRegexp("Content-Type", "application/(text|json)",
+//               "X-Requested-With", "XMLHttpRequest")
+//
+// The above route will only match if both the request header matches both regular expressions.
+// If the value is an empty string, it will match any value if the key is set.
+// Use the start and end of string anchors (^ and $) to match an exact value.
+func (r *Route) HeadersRegexp(pairs ...string) *Route {
+	if r.err == nil {
+		var headers map[string]*regexp.Regexp
+		headers, r.err = mapFromPairsToRegex(pairs...)
+		return r.addMatcher(headerRegexMatcher(headers))
+	}
+	return r
+}
+
+// Host -----------------------------------------------------------------------
+
+// Host adds a matcher for the URL host.
+// It accepts a template with zero or more URL variables enclosed by {}.
+// Variables can define an optional regexp pattern to be matched:
+//
+// - {name} matches anything until the next dot.
+//
+// - {name:pattern} matches the given regexp pattern.
+//
+// For example:
+//
+//     r := mux.NewRouter()
+//     r.Host("www.example.com")
+//     r.Host("{subdomain}.domain.com")
+//     r.Host("{subdomain:[a-z]+}.domain.com")
+//
+// Variable names must be unique in a given route. They can be retrieved
+// calling mux.Vars(request).
+func (r *Route) Host(tpl string) *Route {
+	r.err = r.addRegexpMatcher(tpl, regexpTypeHost)
+	return r
+}
+
+// MatcherFunc ----------------------------------------------------------------
+
+// MatcherFunc is the function signature used by custom matchers.
+type MatcherFunc func(*http.Request, *RouteMatch) bool
+
+// Match returns the match for a given request.
+func (m MatcherFunc) Match(r *http.Request, match *RouteMatch) bool {
+	return m(r, match)
+}
+
+// MatcherFunc adds a custom function to be used as request matcher.
+func (r *Route) MatcherFunc(f MatcherFunc) *Route {
+	return r.addMatcher(f)
+}
+
+// Methods --------------------------------------------------------------------
+
+// methodMatcher matches the request against HTTP methods.
+type methodMatcher []string
+
+func (m methodMatcher) Match(r *http.Request, match *RouteMatch) bool {
+	return matchInArray(m, r.Method)
+}
+
+// Methods adds a matcher for HTTP methods.
+// It accepts a sequence of one or more methods to be matched, e.g.:
+// "GET", "POST", "PUT".
+func (r *Route) Methods(methods ...string) *Route {
+	for k, v := range methods {
+		methods[k] = strings.ToUpper(v)
+	}
+	return r.addMatcher(methodMatcher(methods))
+}
+
+// Path -----------------------------------------------------------------------
+
+// Path adds a matcher for the URL path.
+// It accepts a template with zero or more URL variables enclosed by {}. The
+// template must start with a "/".
+// Variables can define an optional regexp pattern to be matched:
+//
+// - {name} matches anything until the next slash.
+//
+// - {name:pattern} matches the given regexp pattern.
+//
+// For example:
+//
+//     r := mux.NewRouter()
+//     r.Path("/products/").Handler(ProductsHandler)
+//     r.Path("/products/{key}").Handler(ProductsHandler)
+//     r.Path("/articles/{category}/{id:[0-9]+}").
+//       Handler(ArticleHandler)
+//
+// Variable names must be unique in a given route. They can be retrieved
+// calling mux.Vars(request).
+func (r *Route) Path(tpl string) *Route {
+	r.err = r.addRegexpMatcher(tpl, regexpTypePath)
+	return r
+}
+
+// PathPrefix -----------------------------------------------------------------
+
+// PathPrefix adds a matcher for the URL path prefix. This matches if the given
+// template is a prefix of the full URL path. See Route.Path() for details on
+// the tpl argument.
+//
+// Note that it does not treat slashes specially ("/foobar/" will be matched by
+// the prefix "/foo") so you may want to use a trailing slash here.
+//
+// Also note that the setting of Router.StrictSlash() has no effect on routes
+// with a PathPrefix matcher.
+func (r *Route) PathPrefix(tpl string) *Route {
+	r.err = r.addRegexpMatcher(tpl, regexpTypePrefix)
+	return r
+}
+
+// Query ----------------------------------------------------------------------
+
+// Queries adds a matcher for URL query values.
+// It accepts a sequence of key/value pairs. Values may define variables.
+// For example:
+//
+//     r := mux.NewRouter()
+//     r.Queries("foo", "bar", "id", "{id:[0-9]+}")
+//
+// The above route will only match if the URL contains the defined queries
+// values, e.g.: ?foo=bar&id=42.
+//
+// It the value is an empty string, it will match any value if the key is set.
+//
+// Variables can define an optional regexp pattern to be matched:
+//
+// - {name} matches anything until the next slash.
+//
+// - {name:pattern} matches the given regexp pattern.
+func (r *Route) Queries(pairs ...string) *Route {
+	length := len(pairs)
+	if length%2 != 0 {
+		r.err = fmt.Errorf(
+			"mux: number of parameters must be multiple of 2, got %v", pairs)
+		return nil
+	}
+	for i := 0; i < length; i += 2 {
+		if r.err = r.addRegexpMatcher(pairs[i]+"="+pairs[i+1], regexpTypeQuery); r.err != nil {
+			return r
+		}
+	}
+
+	return r
+}
+
+// Schemes --------------------------------------------------------------------
+
+// schemeMatcher matches the request against URL schemes.
+type schemeMatcher []string
+
+func (m schemeMatcher) Match(r *http.Request, match *RouteMatch) bool {
+	return matchInArray(m, r.URL.Scheme)
+}
+
+// Schemes adds a matcher for URL schemes.
+// It accepts a sequence of schemes to be matched, e.g.: "http", "https".
+func (r *Route) Schemes(schemes ...string) *Route {
+	for k, v := range schemes {
+		schemes[k] = strings.ToLower(v)
+	}
+	if r.buildScheme == "" && len(schemes) > 0 {
+		r.buildScheme = schemes[0]
+	}
+	return r.addMatcher(schemeMatcher(schemes))
+}
+
+// BuildVarsFunc --------------------------------------------------------------
+
+// BuildVarsFunc is the function signature used by custom build variable
+// functions (which can modify route variables before a route's URL is built).
+type BuildVarsFunc func(map[string]string) map[string]string
+
+// BuildVarsFunc adds a custom function to be used to modify build variables
+// before a route's URL is built.
+func (r *Route) BuildVarsFunc(f BuildVarsFunc) *Route {
+	r.buildVarsFunc = f
+	return r
+}
+
+// Subrouter ------------------------------------------------------------------
+
+// Subrouter creates a subrouter for the route.
+//
+// It will test the inner routes only if the parent route matched. For example:
+//
+//     r := mux.NewRouter()
+//     s := r.Host("www.example.com").Subrouter()
+//     s.HandleFunc("/products/", ProductsHandler)
+//     s.HandleFunc("/products/{key}", ProductHandler)
+//     s.HandleFunc("/articles/{category}/{id:[0-9]+}"), ArticleHandler)
+//
+// Here, the routes registered in the subrouter won't be tested if the host
+// doesn't match.
+func (r *Route) Subrouter() *Router {
+	router := &Router{parent: r, strictSlash: r.strictSlash}
+	r.addMatcher(router)
+	return router
+}
+
+// ----------------------------------------------------------------------------
+// URL building
+// ----------------------------------------------------------------------------
+
+// URL builds a URL for the route.
+//
+// It accepts a sequence of key/value pairs for the route variables. For
+// example, given this route:
+//
+//     r := mux.NewRouter()
+//     r.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler).
+//       Name("article")
+//
+// ...a URL for it can be built using:
+//
+//     url, err := r.Get("article").URL("category", "technology", "id", "42")
+//
+// ...which will return an url.URL with the following path:
+//
+//     "/articles/technology/42"
+//
+// This also works for host variables:
+//
+//     r := mux.NewRouter()
+//     r.Host("{subdomain}.domain.com").
+//       HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler).
+//       Name("article")
+//
+//     // url.String() will be "http://news.domain.com/articles/technology/42"
+//     url, err := r.Get("article").URL("subdomain", "news",
+//                                      "category", "technology",
+//                                      "id", "42")
+//
+// All variables defined in the route are required, and their values must
+// conform to the corresponding patterns.
+func (r *Route) URL(pairs ...string) (*url.URL, error) {
+	if r.err != nil {
+		return nil, r.err
+	}
+	if r.regexp == nil {
+		return nil, errors.New("mux: route doesn't have a host or path")
+	}
+	values, err := r.prepareVars(pairs...)
+	if err != nil {
+		return nil, err
+	}
+	var scheme, host, path string
+	queries := make([]string, 0, len(r.regexp.queries))
+	if r.regexp.host != nil {
+		if host, err = r.regexp.host.url(values); err != nil {
+			return nil, err
+		}
+		scheme = "http"
+		if s := r.getBuildScheme(); s != "" {
+			scheme = s
+		}
+	}
+	if r.regexp.path != nil {
+		if path, err = r.regexp.path.url(values); err != nil {
+			return nil, err
+		}
+	}
+	for _, q := range r.regexp.queries {
+		var query string
+		if query, err = q.url(values); err != nil {
+			return nil, err
+		}
+		queries = append(queries, query)
+	}
+	return &url.URL{
+		Scheme:   scheme,
+		Host:     host,
+		Path:     path,
+		RawQuery: strings.Join(queries, "&"),
+	}, nil
+}
+
+// URLHost builds the host part of the URL for a route. See Route.URL().
+//
+// The route must have a host defined.
+func (r *Route) URLHost(pairs ...string) (*url.URL, error) {
+	if r.err != nil {
+		return nil, r.err
+	}
+	if r.regexp == nil || r.regexp.host == nil {
+		return nil, errors.New("mux: route doesn't have a host")
+	}
+	values, err := r.prepareVars(pairs...)
+	if err != nil {
+		return nil, err
+	}
+	host, err := r.regexp.host.url(values)
+	if err != nil {
+		return nil, err
+	}
+	u := &url.URL{
+		Scheme: "http",
+		Host:   host,
+	}
+	if s := r.getBuildScheme(); s != "" {
+		u.Scheme = s
+	}
+	return u, nil
+}
+
+// URLPath builds the path part of the URL for a route. See Route.URL().
+//
+// The route must have a path defined.
+func (r *Route) URLPath(pairs ...string) (*url.URL, error) {
+	if r.err != nil {
+		return nil, r.err
+	}
+	if r.regexp == nil || r.regexp.path == nil {
+		return nil, errors.New("mux: route doesn't have a path")
+	}
+	values, err := r.prepareVars(pairs...)
+	if err != nil {
+		return nil, err
+	}
+	path, err := r.regexp.path.url(values)
+	if err != nil {
+		return nil, err
+	}
+	return &url.URL{
+		Path: path,
+	}, nil
+}
+
+// GetPathTemplate returns the template used to build the
+// route match.
+// This is useful for building simple REST API documentation and for instrumentation
+// against third-party services.
+// An error will be returned if the route does not define a path.
+func (r *Route) GetPathTemplate() (string, error) {
+	if r.err != nil {
+		return "", r.err
+	}
+	if r.regexp == nil || r.regexp.path == nil {
+		return "", errors.New("mux: route doesn't have a path")
+	}
+	return r.regexp.path.template, nil
+}
+
+// GetPathRegexp returns the expanded regular expression used to match route path.
+// This is useful for building simple REST API documentation and for instrumentation
+// against third-party services.
+// An error will be returned if the route does not define a path.
+func (r *Route) GetPathRegexp() (string, error) {
+	if r.err != nil {
+		return "", r.err
+	}
+	if r.regexp == nil || r.regexp.path == nil {
+		return "", errors.New("mux: route does not have a path")
+	}
+	return r.regexp.path.regexp.String(), nil
+}
+
+// GetQueriesRegexp returns the expanded regular expressions used to match the
+// route queries.
+// This is useful for building simple REST API documentation and for instrumentation
+// against third-party services.
+// An empty list will be returned if the route does not have queries.
+func (r *Route) GetQueriesRegexp() ([]string, error) {
+	if r.err != nil {
+		return nil, r.err
+	}
+	if r.regexp == nil || r.regexp.queries == nil {
+		return nil, errors.New("mux: route doesn't have queries")
+	}
+	var queries []string
+	for _, query := range r.regexp.queries {
+		queries = append(queries, query.regexp.String())
+	}
+	return queries, nil
+}
+
+// GetQueriesTemplates returns the templates used to build the
+// query matching.
+// This is useful for building simple REST API documentation and for instrumentation
+// against third-party services.
+// An empty list will be returned if the route does not define queries.
+func (r *Route) GetQueriesTemplates() ([]string, error) {
+	if r.err != nil {
+		return nil, r.err
+	}
+	if r.regexp == nil || r.regexp.queries == nil {
+		return nil, errors.New("mux: route doesn't have queries")
+	}
+	var queries []string
+	for _, query := range r.regexp.queries {
+		queries = append(queries, query.template)
+	}
+	return queries, nil
+}
+
+// GetMethods returns the methods the route matches against
+// This is useful for building simple REST API documentation and for instrumentation
+// against third-party services.
+// An empty list will be returned if route does not have methods.
+func (r *Route) GetMethods() ([]string, error) {
+	if r.err != nil {
+		return nil, r.err
+	}
+	for _, m := range r.matchers {
+		if methods, ok := m.(methodMatcher); ok {
+			return []string(methods), nil
+		}
+	}
+	return nil, nil
+}
+
+// GetHostTemplate returns the template used to build the
+// route match.
+// This is useful for building simple REST API documentation and for instrumentation
+// against third-party services.
+// An error will be returned if the route does not define a host.
+func (r *Route) GetHostTemplate() (string, error) {
+	if r.err != nil {
+		return "", r.err
+	}
+	if r.regexp == nil || r.regexp.host == nil {
+		return "", errors.New("mux: route doesn't have a host")
+	}
+	return r.regexp.host.template, nil
+}
+
+// prepareVars converts the route variable pairs into a map. If the route has a
+// BuildVarsFunc, it is invoked.
+func (r *Route) prepareVars(pairs ...string) (map[string]string, error) {
+	m, err := mapFromPairsToString(pairs...)
+	if err != nil {
+		return nil, err
+	}
+	return r.buildVars(m), nil
+}
+
+func (r *Route) buildVars(m map[string]string) map[string]string {
+	if r.parent != nil {
+		m = r.parent.buildVars(m)
+	}
+	if r.buildVarsFunc != nil {
+		m = r.buildVarsFunc(m)
+	}
+	return m
+}
+
+// ----------------------------------------------------------------------------
+// parentRoute
+// ----------------------------------------------------------------------------
+
+// parentRoute allows routes to know about parent host and path definitions.
+type parentRoute interface {
+	getBuildScheme() string
+	getNamedRoutes() map[string]*Route
+	getRegexpGroup() *routeRegexpGroup
+	buildVars(map[string]string) map[string]string
+}
+
+func (r *Route) getBuildScheme() string {
+	if r.buildScheme != "" {
+		return r.buildScheme
+	}
+	if r.parent != nil {
+		return r.parent.getBuildScheme()
+	}
+	return ""
+}
+
+// getNamedRoutes returns the map where named routes are registered.
+func (r *Route) getNamedRoutes() map[string]*Route {
+	if r.parent == nil {
+		// During tests router is not always set.
+		r.parent = NewRouter()
+	}
+	return r.parent.getNamedRoutes()
+}
+
+// getRegexpGroup returns regexp definitions from this route.
+func (r *Route) getRegexpGroup() *routeRegexpGroup {
+	if r.regexp == nil {
+		if r.parent == nil {
+			// During tests router is not always set.
+			r.parent = NewRouter()
+		}
+		regexp := r.parent.getRegexpGroup()
+		if regexp == nil {
+			r.regexp = new(routeRegexpGroup)
+		} else {
+			// Copy.
+			r.regexp = &routeRegexpGroup{
+				host:    regexp.host,
+				path:    regexp.path,
+				queries: regexp.queries,
+			}
+		}
+	}
+	return r.regexp
+}
diff --git a/vendor/github.com/gorilla/mux/test_helpers.go b/vendor/github.com/gorilla/mux/test_helpers.go
new file mode 100644
index 0000000..8b2c4a4
--- /dev/null
+++ b/vendor/github.com/gorilla/mux/test_helpers.go
@@ -0,0 +1,18 @@
+// Copyright 2012 The Gorilla Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mux
+
+import "net/http"
+
+// SetURLVars sets the URL variables for the given request, to be accessed via
+// mux.Vars for testing route behaviour.
+//
+// This API should only be used for testing purposes; it provides a way to
+// inject variables into the request context. Alternatively, URL variables
+// can be set by making a route that captures the required variables,
+// starting a server and sending the request to that server.
+func SetURLVars(r *http.Request, val map[string]string) *http.Request {
+	return setVars(r, val)
+}
diff --git a/vendor/github.com/justinas/alice/.travis.yml b/vendor/github.com/justinas/alice/.travis.yml
new file mode 100644
index 0000000..dc6bea6
--- /dev/null
+++ b/vendor/github.com/justinas/alice/.travis.yml
@@ -0,0 +1,17 @@
+language: go
+
+matrix:
+  include:
+    - go: 1.0.x
+    - go: 1.1.x
+    - go: 1.2.x
+    - go: 1.3.x
+    - go: 1.4.x
+    - go: 1.5.x
+    - go: 1.6.x
+    - go: 1.7.x
+    - go: 1.8.x
+    - go: 1.9.x
+    - go: tip
+  allow_failures:
+    - go: tip
diff --git a/vendor/github.com/justinas/alice/LICENSE b/vendor/github.com/justinas/alice/LICENSE
new file mode 100644
index 0000000..0d0d352
--- /dev/null
+++ b/vendor/github.com/justinas/alice/LICENSE
@@ -0,0 +1,20 @@
+The MIT License (MIT)
+
+Copyright (c) 2014 Justinas Stankevicius
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/vendor/github.com/justinas/alice/README.md b/vendor/github.com/justinas/alice/README.md
new file mode 100644
index 0000000..e4f9157
--- /dev/null
+++ b/vendor/github.com/justinas/alice/README.md
@@ -0,0 +1,98 @@
+# Alice 
+
+[![GoDoc](https://godoc.org/github.com/golang/gddo?status.svg)](http://godoc.org/github.com/justinas/alice)
+[![Build Status](https://travis-ci.org/justinas/alice.svg?branch=master)](https://travis-ci.org/justinas/alice)
+[![Coverage](http://gocover.io/_badge/github.com/justinas/alice)](http://gocover.io/github.com/justinas/alice)
+
+Alice provides a convenient way to chain 
+your HTTP middleware functions and the app handler.
+
+In short, it transforms
+
+```go
+Middleware1(Middleware2(Middleware3(App)))
+```
+
+to
+
+```go
+alice.New(Middleware1, Middleware2, Middleware3).Then(App)
+```
+
+### Why?
+
+None of the other middleware chaining solutions
+behaves exactly like Alice.
+Alice is as minimal as it gets:
+in essence, it's just a for loop that does the wrapping for you.
+
+Check out [this blog post](http://justinas.org/alice-painless-middleware-chaining-for-go/)
+for explanation how Alice is different from other chaining solutions.
+
+### Usage
+
+Your middleware constructors should have the form of
+
+```go
+func (http.Handler) http.Handler
+```
+
+Some middleware provide this out of the box.
+For ones that don't, it's trivial to write one yourself.
+
+```go
+func myStripPrefix(h http.Handler) http.Handler {
+    return http.StripPrefix("/old", h)
+}
+```
+
+This complete example shows the full power of Alice.
+
+```go
+package main
+
+import (
+    "net/http"
+    "time"
+
+    "github.com/throttled/throttled"
+    "github.com/justinas/alice"
+    "github.com/justinas/nosurf"
+)
+
+func timeoutHandler(h http.Handler) http.Handler {
+    return http.TimeoutHandler(h, 1*time.Second, "timed out")
+}
+
+func myApp(w http.ResponseWriter, r *http.Request) {
+    w.Write([]byte("Hello world!"))
+}
+
+func main() {
+    th := throttled.Interval(throttled.PerSec(10), 1, &throttled.VaryBy{Path: true}, 50)
+    myHandler := http.HandlerFunc(myApp)
+
+    chain := alice.New(th.Throttle, timeoutHandler, nosurf.NewPure).Then(myHandler)
+    http.ListenAndServe(":8000", chain)
+}
+```
+
+Here, the request will pass [throttled](https://github.com/PuerkitoBio/throttled) first,
+then an http.TimeoutHandler we've set up,
+then [nosurf](https://github.com/justinas/nosurf)
+and will finally reach our handler.
+
+Note that Alice makes **no guarantees** for
+how one or another piece of  middleware will behave.
+Once it passes the execution to the outer layer of middleware,
+it has no saying in whether middleware will execute the inner handlers.
+This is intentional behavior.
+
+Alice works with Go 1.0 and higher.
+
+### Contributing
+
+0. Find an issue that bugs you / open a new one.
+1. Discuss.
+2. Branch off, commit, test.
+3. Make a pull request / attach the commits to the issue.
diff --git a/vendor/github.com/justinas/alice/chain.go b/vendor/github.com/justinas/alice/chain.go
new file mode 100644
index 0000000..da0e2b5
--- /dev/null
+++ b/vendor/github.com/justinas/alice/chain.go
@@ -0,0 +1,112 @@
+// Package alice provides a convenient way to chain http handlers.
+package alice
+
+import "net/http"
+
+// A constructor for a piece of middleware.
+// Some middleware use this constructor out of the box,
+// so in most cases you can just pass somepackage.New
+type Constructor func(http.Handler) http.Handler
+
+// Chain acts as a list of http.Handler constructors.
+// Chain is effectively immutable:
+// once created, it will always hold
+// the same set of constructors in the same order.
+type Chain struct {
+	constructors []Constructor
+}
+
+// New creates a new chain,
+// memorizing the given list of middleware constructors.
+// New serves no other function,
+// constructors are only called upon a call to Then().
+func New(constructors ...Constructor) Chain {
+	return Chain{append(([]Constructor)(nil), constructors...)}
+}
+
+// Then chains the middleware and returns the final http.Handler.
+//     New(m1, m2, m3).Then(h)
+// is equivalent to:
+//     m1(m2(m3(h)))
+// When the request comes in, it will be passed to m1, then m2, then m3
+// and finally, the given handler
+// (assuming every middleware calls the following one).
+//
+// A chain can be safely reused by calling Then() several times.
+//     stdStack := alice.New(ratelimitHandler, csrfHandler)
+//     indexPipe = stdStack.Then(indexHandler)
+//     authPipe = stdStack.Then(authHandler)
+// Note that constructors are called on every call to Then()
+// and thus several instances of the same middleware will be created
+// when a chain is reused in this way.
+// For proper middleware, this should cause no problems.
+//
+// Then() treats nil as http.DefaultServeMux.
+func (c Chain) Then(h http.Handler) http.Handler {
+	if h == nil {
+		h = http.DefaultServeMux
+	}
+
+	for i := range c.constructors {
+		h = c.constructors[len(c.constructors)-1-i](h)
+	}
+
+	return h
+}
+
+// ThenFunc works identically to Then, but takes
+// a HandlerFunc instead of a Handler.
+//
+// The following two statements are equivalent:
+//     c.Then(http.HandlerFunc(fn))
+//     c.ThenFunc(fn)
+//
+// ThenFunc provides all the guarantees of Then.
+func (c Chain) ThenFunc(fn http.HandlerFunc) http.Handler {
+	if fn == nil {
+		return c.Then(nil)
+	}
+	return c.Then(fn)
+}
+
+// Append extends a chain, adding the specified constructors
+// as the last ones in the request flow.
+//
+// Append returns a new chain, leaving the original one untouched.
+//
+//     stdChain := alice.New(m1, m2)
+//     extChain := stdChain.Append(m3, m4)
+//     // requests in stdChain go m1 -> m2
+//     // requests in extChain go m1 -> m2 -> m3 -> m4
+func (c Chain) Append(constructors ...Constructor) Chain {
+	newCons := make([]Constructor, 0, len(c.constructors)+len(constructors))
+	newCons = append(newCons, c.constructors...)
+	newCons = append(newCons, constructors...)
+
+	return Chain{newCons}
+}
+
+// Extend extends a chain by adding the specified chain
+// as the last one in the request flow.
+//
+// Extend returns a new chain, leaving the original one untouched.
+//
+//     stdChain := alice.New(m1, m2)
+//     ext1Chain := alice.New(m3, m4)
+//     ext2Chain := stdChain.Extend(ext1Chain)
+//     // requests in stdChain go  m1 -> m2
+//     // requests in ext1Chain go m3 -> m4
+//     // requests in ext2Chain go m1 -> m2 -> m3 -> m4
+//
+// Another example:
+//  aHtmlAfterNosurf := alice.New(m2)
+// 	aHtml := alice.New(m1, func(h http.Handler) http.Handler {
+// 		csrf := nosurf.New(h)
+// 		csrf.SetFailureHandler(aHtmlAfterNosurf.ThenFunc(csrfFail))
+// 		return csrf
+// 	}).Extend(aHtmlAfterNosurf)
+//		// requests to aHtml hitting nosurfs success handler go m1 -> nosurf -> m2 -> target-handler
+//		// requests to aHtml hitting nosurfs failure handler go m1 -> nosurf -> m2 -> csrfFail
+func (c Chain) Extend(chain Chain) Chain {
+	return c.Append(chain.constructors...)
+}
diff --git a/vendor/github.com/kr/logfmt/.gitignore b/vendor/github.com/kr/logfmt/.gitignore
new file mode 100644
index 0000000..8e524f6
--- /dev/null
+++ b/vendor/github.com/kr/logfmt/.gitignore
@@ -0,0 +1,3 @@
+*.test
+*.swp
+*.prof
diff --git a/vendor/github.com/kr/logfmt/Readme b/vendor/github.com/kr/logfmt/Readme
new file mode 100644
index 0000000..1865a11
--- /dev/null
+++ b/vendor/github.com/kr/logfmt/Readme
@@ -0,0 +1,12 @@
+Go package for parsing (and, eventually, generating)
+log lines in the logfmt style.
+
+See http://godoc.org/github.com/kr/logfmt for format, and other documentation and examples.
+
+Copyright (C) 2013 Keith Rarick, Blake Mizerany
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/vendor/github.com/kr/logfmt/decode.go b/vendor/github.com/kr/logfmt/decode.go
new file mode 100644
index 0000000..1397fb7
--- /dev/null
+++ b/vendor/github.com/kr/logfmt/decode.go
@@ -0,0 +1,184 @@
+// Package implements the decoding of logfmt key-value pairs.
+//
+// Example logfmt message:
+//
+//	foo=bar a=14 baz="hello kitty" cool%story=bro f %^asdf
+//
+// Example result in JSON:
+//
+//	{ "foo": "bar", "a": 14, "baz": "hello kitty", "cool%story": "bro", "f": true, "%^asdf": true }
+//
+// EBNFish:
+//
+// 	ident_byte = any byte greater than ' ', excluding '=' and '"'
+// 	string_byte = any byte excluding '"' and '\'
+// 	garbage = !ident_byte
+// 	ident = ident_byte, { ident byte }
+// 	key = ident
+// 	value = ident | '"', { string_byte | '\', '"' }, '"'
+// 	pair = key, '=', value | key, '=' | key
+// 	message = { garbage, pair }, garbage
+package logfmt
+
+import (
+	"reflect"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// Handler is the interface implemented by objects that accept logfmt
+// key-value pairs. HandleLogfmt must copy the logfmt data if it
+// wishes to retain the data after returning.
+type Handler interface {
+	HandleLogfmt(key, val []byte) error
+}
+
+// The HandlerFunc type is an adapter to allow the use of ordinary functions as
+// logfmt handlers. If f is a function with the appropriate signature,
+// HandlerFunc(f) is a Handler object that calls f.
+type HandlerFunc func(key, val []byte) error
+
+func (f HandlerFunc) HandleLogfmt(key, val []byte) error {
+	return f(key, val)
+}
+
+// Unmarshal parses the logfmt encoding data and stores the result in the value
+// pointed to by v. If v is an Handler, HandleLogfmt will be called for each
+// key-value pair.
+//
+// If v is not a Handler, it will pass v to NewStructHandler and use the
+// returned StructHandler for decoding.
+func Unmarshal(data []byte, v interface{}) (err error) {
+	h, ok := v.(Handler)
+	if !ok {
+		h, err = NewStructHandler(v)
+		if err != nil {
+			return err
+		}
+	}
+	return gotoScanner(data, h)
+}
+
+// StructHandler unmarshals logfmt into a struct. It matches incoming keys to
+// the the struct's fields (either the struct field name or its tag, preferring
+// an exact match but also accepting a case-insensitive match.
+//
+// Field types supported by StructHandler are:
+//
+// 	all numeric types (e.g. float32, int, etc.)
+// 	[]byte
+// 	string
+// 	bool - true if key is present, false otherwise (the value is ignored).
+//	time.Duration - uses time.ParseDuration
+//
+// If a field is a pointer to an above type, and a matching key is not present
+// in the logfmt data, the pointer will be untouched.
+//
+// If v is not a pointer to an Handler or struct, Unmarshal will return an
+// error.
+type StructHandler struct {
+	rv reflect.Value
+}
+
+func NewStructHandler(v interface{}) (Handler, error) {
+	rv := reflect.ValueOf(v)
+	if rv.Kind() != reflect.Ptr || rv.IsNil() {
+		return nil, &InvalidUnmarshalError{reflect.TypeOf(v)}
+	}
+	return &StructHandler{rv: rv}, nil
+}
+
+func (h *StructHandler) HandleLogfmt(key, val []byte) error {
+	el := h.rv.Elem()
+	skey := string(key)
+	for i := 0; i < el.NumField(); i++ {
+		fv := el.Field(i)
+		ft := el.Type().Field(i)
+		switch {
+		case ft.Name == skey:
+		case ft.Tag.Get("logfmt") == skey:
+		case strings.EqualFold(ft.Name, skey):
+		default:
+			continue
+		}
+		if fv.Kind() == reflect.Ptr {
+			if fv.IsNil() {
+				t := fv.Type().Elem()
+				v := reflect.New(t)
+				fv.Set(v)
+				fv = v
+			}
+			fv = fv.Elem()
+		}
+		switch fv.Interface().(type) {
+		case time.Duration:
+			d, err := time.ParseDuration(string(val))
+			if err != nil {
+				return &UnmarshalTypeError{string(val), fv.Type()}
+			}
+			fv.Set(reflect.ValueOf(d))
+		case string:
+			fv.SetString(string(val))
+		case []byte:
+			b := make([]byte, len(val))
+			copy(b, val)
+			fv.SetBytes(b)
+		case bool:
+			fv.SetBool(true)
+		default:
+			switch {
+			case reflect.Int <= fv.Kind() && fv.Kind() <= reflect.Int64:
+				v, err := strconv.ParseInt(string(val), 10, 64)
+				if err != nil {
+					return err
+				}
+				fv.SetInt(v)
+			case reflect.Uint32 <= fv.Kind() && fv.Kind() <= reflect.Uint64:
+				v, err := strconv.ParseUint(string(val), 10, 64)
+				if err != nil {
+					return err
+				}
+				fv.SetUint(v)
+			case reflect.Float32 <= fv.Kind() && fv.Kind() <= reflect.Float64:
+				v, err := strconv.ParseFloat(string(val), 10)
+				if err != nil {
+					return err
+				}
+				fv.SetFloat(v)
+			default:
+				return &UnmarshalTypeError{string(val), fv.Type()}
+			}
+		}
+
+	}
+	return nil
+}
+
+// An InvalidUnmarshalError describes an invalid argument passed to Unmarshal.
+// (The argument to Unmarshal must be a non-nil pointer.)
+type InvalidUnmarshalError struct {
+	Type reflect.Type
+}
+
+func (e *InvalidUnmarshalError) Error() string {
+	if e.Type == nil {
+		return "logfmt: Unmarshal(nil)"
+	}
+
+	if e.Type.Kind() != reflect.Ptr {
+		return "logfmt: Unmarshal(non-pointer " + e.Type.String() + ")"
+	}
+	return "logfmt: Unmarshal(nil " + e.Type.String() + ")"
+}
+
+// An UnmarshalTypeError describes a logfmt value that was
+// not appropriate for a value of a specific Go type.
+type UnmarshalTypeError struct {
+	Value string       // the logfmt value
+	Type  reflect.Type // type of Go value it could not be assigned to
+}
+
+func (e *UnmarshalTypeError) Error() string {
+	return "logfmt: cannot unmarshal " + e.Value + " into Go value of type " + e.Type.String()
+}
diff --git a/vendor/github.com/kr/logfmt/scanner.go b/vendor/github.com/kr/logfmt/scanner.go
new file mode 100644
index 0000000..095221f
--- /dev/null
+++ b/vendor/github.com/kr/logfmt/scanner.go
@@ -0,0 +1,149 @@
+package logfmt
+
+import (
+	"errors"
+	"fmt"
+)
+
+var ErrUnterminatedString = errors.New("logfmt: unterminated string")
+
+func gotoScanner(data []byte, h Handler) (err error) {
+	saveError := func(e error) {
+		if err == nil {
+			err = e
+		}
+	}
+
+	var c byte
+	var i int
+	var m int
+	var key []byte
+	var val []byte
+	var ok bool
+	var esc bool
+
+garbage:
+	if i == len(data) {
+		return
+	}
+
+	c = data[i]
+	switch {
+	case c > ' ' && c != '"' && c != '=':
+		key, val = nil, nil
+		m = i
+		i++
+		goto key
+	default:
+		i++
+		goto garbage
+	}
+
+key:
+	if i >= len(data) {
+		if m >= 0 {
+			key = data[m:i]
+			saveError(h.HandleLogfmt(key, nil))
+		}
+		return
+	}
+
+	c = data[i]
+	switch {
+	case c > ' ' && c != '"' && c != '=':
+		i++
+		goto key
+	case c == '=':
+		key = data[m:i]
+		i++
+		goto equal
+	default:
+		key = data[m:i]
+		i++
+		saveError(h.HandleLogfmt(key, nil))
+		goto garbage
+	}
+
+equal:
+	if i >= len(data) {
+		if m >= 0 {
+			i--
+			key = data[m:i]
+			saveError(h.HandleLogfmt(key, nil))
+		}
+		return
+	}
+
+	c = data[i]
+	switch {
+	case c > ' ' && c != '"' && c != '=':
+		m = i
+		i++
+		goto ivalue
+	case c == '"':
+		m = i
+		i++
+		esc = false
+		goto qvalue
+	default:
+		if key != nil {
+			saveError(h.HandleLogfmt(key, val))
+		}
+		i++
+		goto garbage
+	}
+
+ivalue:
+	if i >= len(data) {
+		if m >= 0 {
+			val = data[m:i]
+			saveError(h.HandleLogfmt(key, val))
+		}
+		return
+	}
+
+	c = data[i]
+	switch {
+	case c > ' ' && c != '"' && c != '=':
+		i++
+		goto ivalue
+	default:
+		val = data[m:i]
+		saveError(h.HandleLogfmt(key, val))
+		i++
+		goto garbage
+	}
+
+qvalue:
+	if i >= len(data) {
+		if m >= 0 {
+			saveError(ErrUnterminatedString)
+		}
+		return
+	}
+
+	c = data[i]
+	switch c {
+	case '\\':
+		i += 2
+		esc = true
+		goto qvalue
+	case '"':
+		i++
+		val = data[m:i]
+		if esc {
+			val, ok = unquoteBytes(val)
+			if !ok {
+				saveError(fmt.Errorf("logfmt: error unquoting bytes %q", string(val)))
+				goto garbage
+			}
+		} else {
+			val = val[1 : len(val)-1]
+		}
+		saveError(h.HandleLogfmt(key, val))
+		goto garbage
+	default:
+		i++
+		goto qvalue
+	}
+}
diff --git a/vendor/github.com/kr/logfmt/unquote.go b/vendor/github.com/kr/logfmt/unquote.go
new file mode 100644
index 0000000..fb088a4
--- /dev/null
+++ b/vendor/github.com/kr/logfmt/unquote.go
@@ -0,0 +1,149 @@
+package logfmt
+
+import (
+	"strconv"
+	"unicode"
+	"unicode/utf16"
+	"unicode/utf8"
+)
+
+// Taken from Go's encoding/json
+
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// getu4 decodes \uXXXX from the beginning of s, returning the hex value,
+// or it returns -1.
+func getu4(s []byte) rune {
+	if len(s) < 6 || s[0] != '\\' || s[1] != 'u' {
+		return -1
+	}
+	r, err := strconv.ParseUint(string(s[2:6]), 16, 64)
+	if err != nil {
+		return -1
+	}
+	return rune(r)
+}
+
+// unquote converts a quoted JSON string literal s into an actual string t.
+// The rules are different than for Go, so cannot use strconv.Unquote.
+func unquote(s []byte) (t string, ok bool) {
+	s, ok = unquoteBytes(s)
+	t = string(s)
+	return
+}
+
+func unquoteBytes(s []byte) (t []byte, ok bool) {
+	if len(s) < 2 || s[0] != '"' || s[len(s)-1] != '"' {
+		return
+	}
+	s = s[1 : len(s)-1]
+
+	// Check for unusual characters. If there are none,
+	// then no unquoting is needed, so return a slice of the
+	// original bytes.
+	r := 0
+	for r < len(s) {
+		c := s[r]
+		if c == '\\' || c == '"' || c < ' ' {
+			break
+		}
+		if c < utf8.RuneSelf {
+			r++
+			continue
+		}
+		rr, size := utf8.DecodeRune(s[r:])
+		if rr == utf8.RuneError && size == 1 {
+			break
+		}
+		r += size
+	}
+	if r == len(s) {
+		return s, true
+	}
+
+	b := make([]byte, len(s)+2*utf8.UTFMax)
+	w := copy(b, s[0:r])
+	for r < len(s) {
+		// Out of room?  Can only happen if s is full of
+		// malformed UTF-8 and we're replacing each
+		// byte with RuneError.
+		if w >= len(b)-2*utf8.UTFMax {
+			nb := make([]byte, (len(b)+utf8.UTFMax)*2)
+			copy(nb, b[0:w])
+			b = nb
+		}
+		switch c := s[r]; {
+		case c == '\\':
+			r++
+			if r >= len(s) {
+				return
+			}
+			switch s[r] {
+			default:
+				return
+			case '"', '\\', '/', '\'':
+				b[w] = s[r]
+				r++
+				w++
+			case 'b':
+				b[w] = '\b'
+				r++
+				w++
+			case 'f':
+				b[w] = '\f'
+				r++
+				w++
+			case 'n':
+				b[w] = '\n'
+				r++
+				w++
+			case 'r':
+				b[w] = '\r'
+				r++
+				w++
+			case 't':
+				b[w] = '\t'
+				r++
+				w++
+			case 'u':
+				r--
+				rr := getu4(s[r:])
+				if rr < 0 {
+					return
+				}
+				r += 6
+				if utf16.IsSurrogate(rr) {
+					rr1 := getu4(s[r:])
+					if dec := utf16.DecodeRune(rr, rr1); dec != unicode.ReplacementChar {
+						// A valid pair; consume.
+						r += 6
+						w += utf8.EncodeRune(b[w:], dec)
+						break
+					}
+					// Invalid surrogate; fall back to replacement rune.
+					rr = unicode.ReplacementChar
+				}
+				w += utf8.EncodeRune(b[w:], rr)
+			}
+
+		// Quote, control characters are invalid.
+		case c == '"', c < ' ':
+			return
+
+		// ASCII
+		case c < utf8.RuneSelf:
+			b[w] = c
+			r++
+			w++
+
+		// Coerce to well-formed UTF-8.
+		default:
+			rr, size := utf8.DecodeRune(s[r:])
+			r += size
+			w += utf8.EncodeRune(b[w:], rr)
+		}
+	}
+	return b[0:w], true
+}
diff --git a/vendor/github.com/namsral/flag/LICENSE b/vendor/github.com/namsral/flag/LICENSE
new file mode 100644
index 0000000..0f2498b
--- /dev/null
+++ b/vendor/github.com/namsral/flag/LICENSE
@@ -0,0 +1,27 @@
+Copyright (c) 2012 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
\ No newline at end of file
diff --git a/vendor/github.com/namsral/flag/README.md b/vendor/github.com/namsral/flag/README.md
new file mode 100644
index 0000000..fba5546
--- /dev/null
+++ b/vendor/github.com/namsral/flag/README.md
@@ -0,0 +1,200 @@
+Flag
+===
+
+Flag is a drop in replacement for Go's flag package with the addition to parse files and environment variables. If you support the [twelve-factor app methodology][], Flag complies with the third factor; "Store config in the environment".
+
+[twelve-factor app methodology]: http://12factor.net
+
+An example using a gopher:
+
+```go
+$ cat > gopher.go
+    package main
+
+    import (
+        "fmt"
+    	"github.com/namsral/flag"
+	)
+    
+    var age int
+    
+    flag.IntVar(&age, "age", 0, "age of gopher")
+    flag.Parse()
+    
+    fmt.Print("age:", age)
+
+$ go run gopher.go -age 1
+age: 1
+```
+
+Same code but using an environment variable:
+
+```go
+$ export AGE=2
+$ go run gopher.go
+age: 2
+```
+    
+
+Same code but using a configuration file:
+
+```go
+$ cat > gopher.conf
+age 3
+
+$ go run gopher.go -config gopher.conf
+age: 3
+```
+
+The following table shows how flags are translated to environment variables and configuration files:
+
+| Type   | Flag          | Environment  | File         |
+| ------ | :------------ |:------------ |:------------ |
+| int    | -age 2        | AGE=2        | age 2        |
+| bool   | -female       | FEMALE=true  | female true  |
+| float  | -length 175.5 | LENGTH=175.5 | length 175.5 |
+| string | -name Gloria  | NAME=Gloria  | name Gloria  |
+
+This package is a port of Go's [flag][] package from the standard library with the addition of two functions `ParseEnv` and `ParseFile`.
+
+[flag]: http://golang.org/src/pkg/flagconfiguration
+
+
+Goals
+-----
+
+- Compatability with the original `flag` package
+- Support the [twelve-factor app methodology][]
+- Uniform user experience between the three input methods
+
+
+Why?
+---
+
+Why not use one of the many INI, JSON or YAML parsers?
+
+I find it best practice to have simple configuration options to control the behaviour of an applications when it starts up. Use basic types like ints, floats and strings for configuration options and store more complex data structures in the "datastore" layer.
+
+
+Usage
+---
+
+It's intended for projects which require a simple configuration made available through command-line flags, configuration files and shell environments. It's similar to the original `flag` package.
+
+Example:
+
+```go
+import "github.com/namsral/flag"
+
+flag.String(flag.DefaultConfigFlagname, "", "path to config file")
+flag.Int("age", 24, "help message for age")
+
+flag.Parse()
+```
+
+Order of precedence:
+
+1. Command line options
+2. Environment variables
+3. Configuration file
+4. Default values
+
+
+#### Parsing Configuration Files
+
+Create a configuration file:
+
+```go
+$ cat > ./gopher.conf
+# empty newlines and lines beginning with a "#" character are ignored.
+name bob
+
+# keys and values can also be separated by the "=" character
+age=20
+
+# booleans can be empty, set with 0, 1, true, false, etc
+hacker
+```
+
+Add a "config" flag:
+
+```go
+flag.String(flag.DefaultConfigFlagname, "", "path to config file")
+```
+
+Run the command:
+
+```go
+$ go run ./gopher.go -config ./gopher.conf
+```
+
+The default flag name for the configuration file is "config" and can be changed
+by setting `flag.DefaultConfigFlagname`:
+
+```go
+flag.DefaultConfigFlagname = "conf"
+flag.Parse()
+```
+
+#### Parsing Environment Variables
+
+Environment variables are parsed 1-on-1 with defined flags:
+
+```go
+$ export AGE=44
+$ go run ./gopher.go
+age=44
+```
+
+
+You can also parse prefixed environment variables by setting a prefix name when creating a new empty flag set:
+
+```go
+fs := flag.NewFlagSetWithEnvPrefix(os.Args[0], "GO", 0)
+fs.Int("age", 24, "help message for age")
+fs.Parse(os.Args[1:])
+...
+$ go export GO_AGE=33
+$ go run ./gopher.go
+age=33
+```
+
+
+For more examples see the [examples][] directory in the project repository.
+
+[examples]: https://github.com/namsral/flag/tree/master/examples
+
+That's it.
+
+
+License
+---
+
+
+Copyright (c) 2012 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/github.com/namsral/flag/flag.go b/vendor/github.com/namsral/flag/flag.go
new file mode 100644
index 0000000..9ee1d9c
--- /dev/null
+++ b/vendor/github.com/namsral/flag/flag.go
@@ -0,0 +1,1068 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*Package flag implements command-line flag parsing.
+okdaokddadok
+Usage:
+
+Define flags using flag.String(), Bool(), Int(), etc.
+
+This declares an integer flag, -flagname, stored in the pointer ip, with type *int.
+    import "flag"
+    var ip = flag.Int("flagname", 1234, "help message for flagname")
+If you like, you can bind the flag to a variable using the Var() functions.
+    var flagvar int
+    func init() {
+        flag.IntVar(&flagvar, "flagname", 1234, "help message for flagname")
+    }
+Or you can create custom flags that satisfy the Value interface (with
+pointer receivers) and couple them to flag parsing by
+    flag.Var(&flagVal, "name", "help message for flagname")
+For such flags, the default value is just the initial value of the variable.
+
+After all flags are defined, call
+    flag.Parse()
+to parse the command line into the defined flags.
+
+Flags may then be used directly. If you're using the flags themselves,
+they are all pointers; if you bind to variables, they're values.
+    fmt.Println("ip has value ", *ip)
+    fmt.Println("flagvar has value ", flagvar)
+
+After parsing, the arguments after the flag are available as the
+slice flag.Args() or individually as flag.Arg(i).
+The arguments are indexed from 0 through flag.NArg()-1.
+
+Command line flag syntax:
+    -flag
+    -flag=x
+    -flag x  // non-boolean flags only
+One or two minus signs may be used; they are equivalent.
+The last form is not permitted for boolean flags because the
+meaning of the command
+    cmd -x *
+will change if there is a file called 0, false, etc.  You must
+use the -flag=false form to turn off a boolean flag.
+
+Flag parsing stops just before the first non-flag argument
+("-" is a non-flag argument) or after the terminator "--".
+
+Integer flags accept 1234, 0664, 0x1234 and may be negative.
+Boolean flags may be 1, 0, t, f, true, false, TRUE, FALSE, True, False.
+Duration flags accept any input valid for time.ParseDuration.
+
+The default set of command-line flags is controlled by
+top-level functions.  The FlagSet type allows one to define
+independent sets of flags, such as to implement subcommands
+in a command-line interface. The methods of FlagSet are
+analogous to the top-level functions for the command-line
+flag set.
+*/
+package flag
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// EnvironmentPrefix defines a string that will be implicitely prefixed to a
+// flag name before looking it up in the environment variables.
+var EnvironmentPrefix = ""
+
+// DefaultConfigFlagname defines the flag name of the optional config file
+// path. Used to lookup and parse the config file when a default is set and
+// available on disk.
+var DefaultConfigFlagname = "config"
+
+// ErrHelp is the error returned if the flag -help is invoked but no such flag is defined.
+var ErrHelp = errors.New("flag: help requested")
+
+// -- bool Value
+type boolValue bool
+
+func newBoolValue(val bool, p *bool) *boolValue {
+	*p = val
+	return (*boolValue)(p)
+}
+
+func (b *boolValue) Set(s string) error {
+	v, err := strconv.ParseBool(s)
+	*b = boolValue(v)
+	return err
+}
+
+func (b *boolValue) Get() interface{} { return bool(*b) }
+
+func (b *boolValue) String() string { return fmt.Sprintf("%v", *b) }
+
+func (b *boolValue) IsBoolFlag() bool { return true }
+
+// optional interface to indicate boolean flags that can be
+// supplied without "=value" text
+type boolFlag interface {
+	Value
+	IsBoolFlag() bool
+}
+
+// -- int Value
+type intValue int
+
+func newIntValue(val int, p *int) *intValue {
+	*p = val
+	return (*intValue)(p)
+}
+
+func (i *intValue) Set(s string) error {
+	v, err := strconv.ParseInt(s, 0, 64)
+	*i = intValue(v)
+	return err
+}
+
+func (i *intValue) Get() interface{} { return int(*i) }
+
+func (i *intValue) String() string { return fmt.Sprintf("%v", *i) }
+
+// -- int64 Value
+type int64Value int64
+
+func newInt64Value(val int64, p *int64) *int64Value {
+	*p = val
+	return (*int64Value)(p)
+}
+
+func (i *int64Value) Set(s string) error {
+	v, err := strconv.ParseInt(s, 0, 64)
+	*i = int64Value(v)
+	return err
+}
+
+func (i *int64Value) Get() interface{} { return int64(*i) }
+
+func (i *int64Value) String() string { return fmt.Sprintf("%v", *i) }
+
+// -- uint Value
+type uintValue uint
+
+func newUintValue(val uint, p *uint) *uintValue {
+	*p = val
+	return (*uintValue)(p)
+}
+
+func (i *uintValue) Set(s string) error {
+	v, err := strconv.ParseUint(s, 0, 64)
+	*i = uintValue(v)
+	return err
+}
+
+func (i *uintValue) Get() interface{} { return uint(*i) }
+
+func (i *uintValue) String() string { return fmt.Sprintf("%v", *i) }
+
+// -- uint64 Value
+type uint64Value uint64
+
+func newUint64Value(val uint64, p *uint64) *uint64Value {
+	*p = val
+	return (*uint64Value)(p)
+}
+
+func (i *uint64Value) Set(s string) error {
+	v, err := strconv.ParseUint(s, 0, 64)
+	*i = uint64Value(v)
+	return err
+}
+
+func (i *uint64Value) Get() interface{} { return uint64(*i) }
+
+func (i *uint64Value) String() string { return fmt.Sprintf("%v", *i) }
+
+// -- string Value
+type stringValue string
+
+func newStringValue(val string, p *string) *stringValue {
+	*p = val
+	return (*stringValue)(p)
+}
+
+func (s *stringValue) Set(val string) error {
+	*s = stringValue(val)
+	return nil
+}
+
+func (s *stringValue) Get() interface{} { return string(*s) }
+
+func (s *stringValue) String() string { return fmt.Sprintf("%s", *s) }
+
+// -- float64 Value
+type float64Value float64
+
+func newFloat64Value(val float64, p *float64) *float64Value {
+	*p = val
+	return (*float64Value)(p)
+}
+
+func (f *float64Value) Set(s string) error {
+	v, err := strconv.ParseFloat(s, 64)
+	*f = float64Value(v)
+	return err
+}
+
+func (f *float64Value) Get() interface{} { return float64(*f) }
+
+func (f *float64Value) String() string { return fmt.Sprintf("%v", *f) }
+
+// -- time.Duration Value
+type durationValue time.Duration
+
+func newDurationValue(val time.Duration, p *time.Duration) *durationValue {
+	*p = val
+	return (*durationValue)(p)
+}
+
+func (d *durationValue) Set(s string) error {
+	v, err := time.ParseDuration(s)
+	*d = durationValue(v)
+	return err
+}
+
+func (d *durationValue) Get() interface{} { return time.Duration(*d) }
+
+func (d *durationValue) String() string { return (*time.Duration)(d).String() }
+
+// Value is the interface to the dynamic value stored in a flag.
+// (The default value is represented as a string.)
+//
+// If a Value has an IsBoolFlag() bool method returning true,
+// the command-line parser makes -name equivalent to -name=true
+// rather than using the next command-line argument.
+type Value interface {
+	String() string
+	Set(string) error
+}
+
+// Getter is an interface that allows the contents of a Value to be retrieved.
+// It wraps the Value interface, rather than being part of it, because it
+// appeared after Go 1 and its compatibility rules. All Value types provided
+// by this package satisfy the Getter interface.
+type Getter interface {
+	Value
+	Get() interface{}
+}
+
+// ErrorHandling defines how to handle flag parsing errors.
+type ErrorHandling int
+
+const (
+	ContinueOnError ErrorHandling = iota
+	ExitOnError
+	PanicOnError
+)
+
+// A FlagSet represents a set of defined flags.  The zero value of a FlagSet
+// has no name and has ContinueOnError error handling.
+type FlagSet struct {
+	// Usage is the function called when an error occurs while parsing flags.
+	// The field is a function (not a method) that may be changed to point to
+	// a custom error handler.
+	Usage func()
+
+	name          string
+	parsed        bool
+	actual        map[string]*Flag
+	formal        map[string]*Flag
+	envPrefix     string   // prefix to all env variable names
+	args          []string // arguments after flags
+	exitOnError   bool     // does the program exit if there's an error?
+	errorHandling ErrorHandling
+	output        io.Writer // nil means stderr; use out() accessor
+}
+
+// A Flag represents the state of a flag.
+type Flag struct {
+	Name     string // name as it appears on command line
+	Usage    string // help message
+	Value    Value  // value as set
+	DefValue string // default value (as text); for usage message
+}
+
+// sortFlags returns the flags as a slice in lexicographical sorted order.
+func sortFlags(flags map[string]*Flag) []*Flag {
+	list := make(sort.StringSlice, len(flags))
+	i := 0
+	for _, f := range flags {
+		list[i] = f.Name
+		i++
+	}
+	list.Sort()
+	result := make([]*Flag, len(list))
+	for i, name := range list {
+		result[i] = flags[name]
+	}
+	return result
+}
+
+func (f *FlagSet) out() io.Writer {
+	if f.output == nil {
+		return os.Stderr
+	}
+	return f.output
+}
+
+// SetOutput sets the destination for usage and error messages.
+// If output is nil, os.Stderr is used.
+func (f *FlagSet) SetOutput(output io.Writer) {
+	f.output = output
+}
+
+// VisitAll visits the flags in lexicographical order, calling fn for each.
+// It visits all flags, even those not set.
+func (f *FlagSet) VisitAll(fn func(*Flag)) {
+	for _, flag := range sortFlags(f.formal) {
+		fn(flag)
+	}
+}
+
+// VisitAll visits the command-line flags in lexicographical order, calling
+// fn for each.  It visits all flags, even those not set.
+func VisitAll(fn func(*Flag)) {
+	CommandLine.VisitAll(fn)
+}
+
+// Visit visits the flags in lexicographical order, calling fn for each.
+// It visits only those flags that have been set.
+func (f *FlagSet) Visit(fn func(*Flag)) {
+	for _, flag := range sortFlags(f.actual) {
+		fn(flag)
+	}
+}
+
+// Visit visits the command-line flags in lexicographical order, calling fn
+// for each.  It visits only those flags that have been set.
+func Visit(fn func(*Flag)) {
+	CommandLine.Visit(fn)
+}
+
+// Lookup returns the Flag structure of the named flag, returning nil if none exists.
+func (f *FlagSet) Lookup(name string) *Flag {
+	return f.formal[name]
+}
+
+// Lookup returns the Flag structure of the named command-line flag,
+// returning nil if none exists.
+func Lookup(name string) *Flag {
+	return CommandLine.formal[name]
+}
+
+// Set sets the value of the named flag.
+func (f *FlagSet) Set(name, value string) error {
+	flag, ok := f.formal[name]
+	if !ok {
+		return fmt.Errorf("no such flag -%v", name)
+	}
+	err := flag.Value.Set(value)
+	if err != nil {
+		return err
+	}
+	if f.actual == nil {
+		f.actual = make(map[string]*Flag)
+	}
+	f.actual[name] = flag
+	return nil
+}
+
+// Set sets the value of the named command-line flag.
+func Set(name, value string) error {
+	return CommandLine.Set(name, value)
+}
+
+// PrintDefaults prints, to standard error unless configured
+// otherwise, the default values of all defined flags in the set.
+func (f *FlagSet) PrintDefaults() {
+	f.VisitAll(func(flag *Flag) {
+		format := "  -%s=%s: %s\n"
+		if _, ok := flag.Value.(*stringValue); ok {
+			// put quotes on the value
+			format = "  -%s=%q: %s\n"
+		}
+		fmt.Fprintf(f.out(), format, flag.Name, flag.DefValue, flag.Usage)
+	})
+}
+
+// PrintDefaults prints to standard error the default values of all defined command-line flags.
+func PrintDefaults() {
+	CommandLine.PrintDefaults()
+}
+
+// defaultUsage is the default function to print a usage message.
+func defaultUsage(f *FlagSet) {
+	if f.name == "" {
+		fmt.Fprintf(f.out(), "Usage:\n")
+	} else {
+		fmt.Fprintf(f.out(), "Usage of %s:\n", f.name)
+	}
+	f.PrintDefaults()
+}
+
+// NOTE: Usage is not just defaultUsage(CommandLine)
+// because it serves (via godoc flag Usage) as the example
+// for how to write your own usage function.
+
+// Usage prints to standard error a usage message documenting all defined command-line flags.
+// The function is a variable that may be changed to point to a custom function.
+var Usage = func() {
+	fmt.Fprintf(os.Stderr, "Usage of %s:\n", os.Args[0])
+	PrintDefaults()
+}
+
+// NFlag returns the number of flags that have been set.
+func (f *FlagSet) NFlag() int { return len(f.actual) }
+
+// NFlag returns the number of command-line flags that have been set.
+func NFlag() int { return len(CommandLine.actual) }
+
+// Arg returns the i'th argument.  Arg(0) is the first remaining argument
+// after flags have been processed.
+func (f *FlagSet) Arg(i int) string {
+	if i < 0 || i >= len(f.args) {
+		return ""
+	}
+	return f.args[i]
+}
+
+// Arg returns the i'th command-line argument.  Arg(0) is the first remaining argument
+// after flags have been processed.
+func Arg(i int) string {
+	return CommandLine.Arg(i)
+}
+
+// NArg is the number of arguments remaining after flags have been processed.
+func (f *FlagSet) NArg() int { return len(f.args) }
+
+// NArg is the number of arguments remaining after flags have been processed.
+func NArg() int { return len(CommandLine.args) }
+
+// Args returns the non-flag arguments.
+func (f *FlagSet) Args() []string { return f.args }
+
+// Args returns the non-flag command-line arguments.
+func Args() []string { return CommandLine.args }
+
+// BoolVar defines a bool flag with specified name, default value, and usage string.
+// The argument p points to a bool variable in which to store the value of the flag.
+func (f *FlagSet) BoolVar(p *bool, name string, value bool, usage string) {
+	f.Var(newBoolValue(value, p), name, usage)
+}
+
+// BoolVar defines a bool flag with specified name, default value, and usage string.
+// The argument p points to a bool variable in which to store the value of the flag.
+func BoolVar(p *bool, name string, value bool, usage string) {
+	CommandLine.Var(newBoolValue(value, p), name, usage)
+}
+
+// Bool defines a bool flag with specified name, default value, and usage string.
+// The return value is the address of a bool variable that stores the value of the flag.
+func (f *FlagSet) Bool(name string, value bool, usage string) *bool {
+	p := new(bool)
+	f.BoolVar(p, name, value, usage)
+	return p
+}
+
+// Bool defines a bool flag with specified name, default value, and usage string.
+// The return value is the address of a bool variable that stores the value of the flag.
+func Bool(name string, value bool, usage string) *bool {
+	return CommandLine.Bool(name, value, usage)
+}
+
+// IntVar defines an int flag with specified name, default value, and usage string.
+// The argument p points to an int variable in which to store the value of the flag.
+func (f *FlagSet) IntVar(p *int, name string, value int, usage string) {
+	f.Var(newIntValue(value, p), name, usage)
+}
+
+// IntVar defines an int flag with specified name, default value, and usage string.
+// The argument p points to an int variable in which to store the value of the flag.
+func IntVar(p *int, name string, value int, usage string) {
+	CommandLine.Var(newIntValue(value, p), name, usage)
+}
+
+// Int defines an int flag with specified name, default value, and usage string.
+// The return value is the address of an int variable that stores the value of the flag.
+func (f *FlagSet) Int(name string, value int, usage string) *int {
+	p := new(int)
+	f.IntVar(p, name, value, usage)
+	return p
+}
+
+// Int defines an int flag with specified name, default value, and usage string.
+// The return value is the address of an int variable that stores the value of the flag.
+func Int(name string, value int, usage string) *int {
+	return CommandLine.Int(name, value, usage)
+}
+
+// Int64Var defines an int64 flag with specified name, default value, and usage string.
+// The argument p points to an int64 variable in which to store the value of the flag.
+func (f *FlagSet) Int64Var(p *int64, name string, value int64, usage string) {
+	f.Var(newInt64Value(value, p), name, usage)
+}
+
+// Int64Var defines an int64 flag with specified name, default value, and usage string.
+// The argument p points to an int64 variable in which to store the value of the flag.
+func Int64Var(p *int64, name string, value int64, usage string) {
+	CommandLine.Var(newInt64Value(value, p), name, usage)
+}
+
+// Int64 defines an int64 flag with specified name, default value, and usage string.
+// The return value is the address of an int64 variable that stores the value of the flag.
+func (f *FlagSet) Int64(name string, value int64, usage string) *int64 {
+	p := new(int64)
+	f.Int64Var(p, name, value, usage)
+	return p
+}
+
+// Int64 defines an int64 flag with specified name, default value, and usage string.
+// The return value is the address of an int64 variable that stores the value of the flag.
+func Int64(name string, value int64, usage string) *int64 {
+	return CommandLine.Int64(name, value, usage)
+}
+
+// UintVar defines a uint flag with specified name, default value, and usage string.
+// The argument p points to a uint variable in which to store the value of the flag.
+func (f *FlagSet) UintVar(p *uint, name string, value uint, usage string) {
+	f.Var(newUintValue(value, p), name, usage)
+}
+
+// UintVar defines a uint flag with specified name, default value, and usage string.
+// The argument p points to a uint  variable in which to store the value of the flag.
+func UintVar(p *uint, name string, value uint, usage string) {
+	CommandLine.Var(newUintValue(value, p), name, usage)
+}
+
+// Uint defines a uint flag with specified name, default value, and usage string.
+// The return value is the address of a uint  variable that stores the value of the flag.
+func (f *FlagSet) Uint(name string, value uint, usage string) *uint {
+	p := new(uint)
+	f.UintVar(p, name, value, usage)
+	return p
+}
+
+// Uint defines a uint flag with specified name, default value, and usage string.
+// The return value is the address of a uint  variable that stores the value of the flag.
+func Uint(name string, value uint, usage string) *uint {
+	return CommandLine.Uint(name, value, usage)
+}
+
+// Uint64Var defines a uint64 flag with specified name, default value, and usage string.
+// The argument p points to a uint64 variable in which to store the value of the flag.
+func (f *FlagSet) Uint64Var(p *uint64, name string, value uint64, usage string) {
+	f.Var(newUint64Value(value, p), name, usage)
+}
+
+// Uint64Var defines a uint64 flag with specified name, default value, and usage string.
+// The argument p points to a uint64 variable in which to store the value of the flag.
+func Uint64Var(p *uint64, name string, value uint64, usage string) {
+	CommandLine.Var(newUint64Value(value, p), name, usage)
+}
+
+// Uint64 defines a uint64 flag with specified name, default value, and usage string.
+// The return value is the address of a uint64 variable that stores the value of the flag.
+func (f *FlagSet) Uint64(name string, value uint64, usage string) *uint64 {
+	p := new(uint64)
+	f.Uint64Var(p, name, value, usage)
+	return p
+}
+
+// Uint64 defines a uint64 flag with specified name, default value, and usage string.
+// The return value is the address of a uint64 variable that stores the value of the flag.
+func Uint64(name string, value uint64, usage string) *uint64 {
+	return CommandLine.Uint64(name, value, usage)
+}
+
+// StringVar defines a string flag with specified name, default value, and usage string.
+// The argument p points to a string variable in which to store the value of the flag.
+func (f *FlagSet) StringVar(p *string, name string, value string, usage string) {
+	f.Var(newStringValue(value, p), name, usage)
+}
+
+// StringVar defines a string flag with specified name, default value, and usage string.
+// The argument p points to a string variable in which to store the value of the flag.
+func StringVar(p *string, name string, value string, usage string) {
+	CommandLine.Var(newStringValue(value, p), name, usage)
+}
+
+// String defines a string flag with specified name, default value, and usage string.
+// The return value is the address of a string variable that stores the value of the flag.
+func (f *FlagSet) String(name string, value string, usage string) *string {
+	p := new(string)
+	f.StringVar(p, name, value, usage)
+	return p
+}
+
+// String defines a string flag with specified name, default value, and usage string.
+// The return value is the address of a string variable that stores the value of the flag.
+func String(name string, value string, usage string) *string {
+	return CommandLine.String(name, value, usage)
+}
+
+// Float64Var defines a float64 flag with specified name, default value, and usage string.
+// The argument p points to a float64 variable in which to store the value of the flag.
+func (f *FlagSet) Float64Var(p *float64, name string, value float64, usage string) {
+	f.Var(newFloat64Value(value, p), name, usage)
+}
+
+// Float64Var defines a float64 flag with specified name, default value, and usage string.
+// The argument p points to a float64 variable in which to store the value of the flag.
+func Float64Var(p *float64, name string, value float64, usage string) {
+	CommandLine.Var(newFloat64Value(value, p), name, usage)
+}
+
+// Float64 defines a float64 flag with specified name, default value, and usage string.
+// The return value is the address of a float64 variable that stores the value of the flag.
+func (f *FlagSet) Float64(name string, value float64, usage string) *float64 {
+	p := new(float64)
+	f.Float64Var(p, name, value, usage)
+	return p
+}
+
+// Float64 defines a float64 flag with specified name, default value, and usage string.
+// The return value is the address of a float64 variable that stores the value of the flag.
+func Float64(name string, value float64, usage string) *float64 {
+	return CommandLine.Float64(name, value, usage)
+}
+
+// DurationVar defines a time.Duration flag with specified name, default value, and usage string.
+// The argument p points to a time.Duration variable in which to store the value of the flag.
+func (f *FlagSet) DurationVar(p *time.Duration, name string, value time.Duration, usage string) {
+	f.Var(newDurationValue(value, p), name, usage)
+}
+
+// DurationVar defines a time.Duration flag with specified name, default value, and usage string.
+// The argument p points to a time.Duration variable in which to store the value of the flag.
+func DurationVar(p *time.Duration, name string, value time.Duration, usage string) {
+	CommandLine.Var(newDurationValue(value, p), name, usage)
+}
+
+// Duration defines a time.Duration flag with specified name, default value, and usage string.
+// The return value is the address of a time.Duration variable that stores the value of the flag.
+func (f *FlagSet) Duration(name string, value time.Duration, usage string) *time.Duration {
+	p := new(time.Duration)
+	f.DurationVar(p, name, value, usage)
+	return p
+}
+
+// Duration defines a time.Duration flag with specified name, default value, and usage string.
+// The return value is the address of a time.Duration variable that stores the value of the flag.
+func Duration(name string, value time.Duration, usage string) *time.Duration {
+	return CommandLine.Duration(name, value, usage)
+}
+
+// Var defines a flag with the specified name and usage string. The type and
+// value of the flag are represented by the first argument, of type Value, which
+// typically holds a user-defined implementation of Value. For instance, the
+// caller could create a flag that turns a comma-separated string into a slice
+// of strings by giving the slice the methods of Value; in particular, Set would
+// decompose the comma-separated string into the slice.
+func (f *FlagSet) Var(value Value, name string, usage string) {
+	// Remember the default value as a string; it won't change.
+	flag := &Flag{name, usage, value, value.String()}
+	_, alreadythere := f.formal[name]
+	if alreadythere {
+		var msg string
+		if f.name == "" {
+			msg = fmt.Sprintf("flag redefined: %s", name)
+		} else {
+			msg = fmt.Sprintf("%s flag redefined: %s", f.name, name)
+		}
+		fmt.Fprintln(f.out(), msg)
+		panic(msg) // Happens only if flags are declared with identical names
+	}
+	if f.formal == nil {
+		f.formal = make(map[string]*Flag)
+	}
+	f.formal[name] = flag
+}
+
+// Var defines a flag with the specified name and usage string. The type and
+// value of the flag are represented by the first argument, of type Value, which
+// typically holds a user-defined implementation of Value. For instance, the
+// caller could create a flag that turns a comma-separated string into a slice
+// of strings by giving the slice the methods of Value; in particular, Set would
+// decompose the comma-separated string into the slice.
+func Var(value Value, name string, usage string) {
+	CommandLine.Var(value, name, usage)
+}
+
+// failf prints to standard error a formatted error and usage message and
+// returns the error.
+func (f *FlagSet) failf(format string, a ...interface{}) error {
+	err := fmt.Errorf(format, a...)
+	fmt.Fprintln(f.out(), err)
+	f.usage()
+	return err
+}
+
+// usage calls the Usage method for the flag set, or the usage function if
+// the flag set is CommandLine.
+func (f *FlagSet) usage() {
+	if f == CommandLine {
+		Usage()
+	} else if f.Usage == nil {
+		defaultUsage(f)
+	} else {
+		f.Usage()
+	}
+}
+
+// parseOne parses one flag. It reports whether a flag was seen.
+func (f *FlagSet) parseOne() (bool, error) {
+	if len(f.args) == 0 {
+		return false, nil
+	}
+	s := f.args[0]
+	if len(s) == 0 || s[0] != '-' || len(s) == 1 {
+		return false, nil
+	}
+	numMinuses := 1
+	if s[1] == '-' {
+		numMinuses++
+		if len(s) == 2 { // "--" terminates the flags
+			f.args = f.args[1:]
+			return false, nil
+		}
+	}
+	name := s[numMinuses:]
+	if len(name) == 0 || name[0] == '-' || name[0] == '=' {
+		return false, f.failf("bad flag syntax: %s", s)
+	}
+
+	// ignore go test flags
+	if strings.HasPrefix(name, "test.") {
+		return false, nil
+	}
+
+	// it's a flag. does it have an argument?
+	f.args = f.args[1:]
+	hasValue := false
+	value := ""
+	for i := 1; i < len(name); i++ { // equals cannot be first
+		if name[i] == '=' {
+			value = name[i+1:]
+			hasValue = true
+			name = name[0:i]
+			break
+		}
+	}
+	m := f.formal
+	flag, alreadythere := m[name] // BUG
+	if !alreadythere {
+		if name == "help" || name == "h" { // special case for nice help message.
+			f.usage()
+			return false, ErrHelp
+		}
+		return false, f.failf("flag provided but not defined: -%s", name)
+	}
+	if fv, ok := flag.Value.(boolFlag); ok && fv.IsBoolFlag() { // special case: doesn't need an arg
+		if hasValue {
+			if err := fv.Set(value); err != nil {
+				return false, f.failf("invalid boolean value %q for  -%s: %v", value, name, err)
+			}
+		} else {
+			fv.Set("true")
+		}
+	} else {
+		// It must have a value, which might be the next argument.
+		if !hasValue && len(f.args) > 0 {
+			// value is the next arg
+			hasValue = true
+			value, f.args = f.args[0], f.args[1:]
+		}
+		if !hasValue {
+			return false, f.failf("flag needs an argument: -%s", name)
+		}
+		if err := flag.Value.Set(value); err != nil {
+			return false, f.failf("invalid value %q for flag -%s: %v", value, name, err)
+		}
+	}
+	if f.actual == nil {
+		f.actual = make(map[string]*Flag)
+	}
+	f.actual[name] = flag
+	return true, nil
+}
+
+// Parse parses flag definitions from the argument list, which should not
+// include the command name.  Must be called after all flags in the FlagSet
+// are defined and before flags are accessed by the program.
+// The return value will be ErrHelp if -help was set but not defined.
+func (f *FlagSet) Parse(arguments []string) error {
+	f.parsed = true
+	f.args = arguments
+	for {
+		seen, err := f.parseOne()
+		if seen {
+			continue
+		}
+		if err == nil {
+			break
+		}
+		switch f.errorHandling {
+		case ContinueOnError:
+			return err
+		case ExitOnError:
+			os.Exit(2)
+		case PanicOnError:
+			panic(err)
+		}
+	}
+
+	// Parse environment variables
+	if err := f.ParseEnv(os.Environ()); err != nil {
+		switch f.errorHandling {
+		case ContinueOnError:
+			return err
+		case ExitOnError:
+			os.Exit(2)
+		case PanicOnError:
+			panic(err)
+		}
+		return err
+	}
+
+	// Parse configuration from file
+	var cFile string
+	if cf := f.formal[DefaultConfigFlagname]; cf != nil {
+		cFile = cf.Value.String()
+	}
+	if cf := f.actual[DefaultConfigFlagname]; cf != nil {
+		cFile = cf.Value.String()
+	}
+	if cFile != "" {
+		if err := f.ParseFile(cFile); err != nil {
+			switch f.errorHandling {
+			case ContinueOnError:
+				return err
+			case ExitOnError:
+				os.Exit(2)
+			case PanicOnError:
+				panic(err)
+			}
+			return err
+		}
+	}
+
+	return nil
+}
+
+// ParseEnv parses flags from environment variables.
+// Flags already set will be ignored.
+func (f *FlagSet) ParseEnv(environ []string) error {
+
+	m := f.formal
+
+	env := make(map[string]string)
+	for _, s := range environ {
+		i := strings.Index(s, "=")
+		if i < 1 {
+			continue
+		}
+		env[s[0:i]] = s[i+1 : len(s)]
+	}
+
+	for _, flag := range m {
+		name := flag.Name
+		_, set := f.actual[name]
+		if set {
+			continue
+		}
+
+		flag, alreadythere := m[name]
+		if !alreadythere {
+			if name == "help" || name == "h" { // special case for nice help message.
+				f.usage()
+				return ErrHelp
+			}
+			return f.failf("environment variable provided but not defined: %s", name)
+		}
+
+		envKey := strings.ToUpper(flag.Name)
+		if f.envPrefix != "" {
+			envKey = f.envPrefix + "_" + envKey
+		}
+		envKey = strings.Replace(envKey, "-", "_", -1)
+
+		value, isSet := env[envKey]
+		if !isSet {
+			continue
+		}
+
+		hasValue := false
+		if len(value) > 0 {
+			hasValue = true
+		}
+
+		if fv, ok := flag.Value.(boolFlag); ok && fv.IsBoolFlag() { // special case: doesn't need an arg
+			if hasValue {
+				if err := fv.Set(value); err != nil {
+					return f.failf("invalid boolean value %q for environment variable %s: %v", value, name, err)
+				}
+			} else {
+				// flag without value is regarded a bool
+				fv.Set("true")
+			}
+		} else {
+			if err := flag.Value.Set(value); err != nil {
+				return f.failf("invalid value %q for environment variable %s: %v", value, name, err)
+			}
+		}
+
+		// update f.actual
+		if f.actual == nil {
+			f.actual = make(map[string]*Flag)
+		}
+		f.actual[name] = flag
+
+	}
+	return nil
+}
+
+// ParseFile parses flags from the file in path.
+// Same format as commandline argumens, newlines and lines beginning with a
+// "#" charater are ignored. Flags already set will be ignored.
+func (f *FlagSet) ParseFile(path string) error {
+
+	// Extract arguments from file
+	fp, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+	defer fp.Close()
+
+	scanner := bufio.NewScanner(fp)
+	for scanner.Scan() {
+		line := scanner.Text()
+
+		// Ignore empty lines
+		if len(line) == 0 {
+			continue
+		}
+
+		// Ignore comments
+		if line[:1] == "#" {
+			continue
+		}
+
+		// Match `key=value` and `key value`
+		var name, value string
+		hasValue := false
+		for i, v := range line {
+			if v == '=' || v == ' ' {
+				hasValue = true
+				name, value = line[:i], line[i+1:]
+				break
+			}
+		}
+
+		if hasValue == false {
+			name = line
+		}
+
+		// Ignore flag when already set; arguments have precedence over file
+		if f.actual[name] != nil {
+			continue
+		}
+
+		m := f.formal
+		flag, alreadythere := m[name]
+		if !alreadythere {
+			if name == "help" || name == "h" { // special case for nice help message.
+				f.usage()
+				return ErrHelp
+			}
+			return f.failf("configuration variable provided but not defined: %s", name)
+		}
+
+		if fv, ok := flag.Value.(boolFlag); ok && fv.IsBoolFlag() { // special case: doesn't need an arg
+			if hasValue {
+				if err := fv.Set(value); err != nil {
+					return f.failf("invalid boolean value %q for configuration variable %s: %v", value, name, err)
+				}
+			} else {
+				// flag without value is regarded a bool
+				fv.Set("true")
+			}
+		} else {
+			if err := flag.Value.Set(value); err != nil {
+				return f.failf("invalid value %q for configuration variable %s: %v", value, name, err)
+			}
+		}
+
+		// update f.actual
+		if f.actual == nil {
+			f.actual = make(map[string]*Flag)
+		}
+		f.actual[name] = flag
+	}
+
+	if err := scanner.Err(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Parsed reports whether f.Parse has been called.
+func (f *FlagSet) Parsed() bool {
+	return f.parsed
+}
+
+// Parse parses the command-line flags from os.Args[1:].  Must be called
+// after all flags are defined and before flags are accessed by the program.
+func Parse() {
+	// Ignore errors; CommandLine is set for ExitOnError.
+	CommandLine.Parse(os.Args[1:])
+}
+
+// Parsed returns true if the command-line flags have been parsed.
+func Parsed() bool {
+	return CommandLine.Parsed()
+}
+
+// CommandLine is the default set of command-line flags, parsed from os.Args.
+// The top-level functions such as BoolVar, Arg, and on are wrappers for the
+// methods of CommandLine.
+var CommandLine = NewFlagSet(os.Args[0], ExitOnError)
+
+// NewFlagSet returns a new, empty flag set with the specified name and
+// error handling property.
+func NewFlagSet(name string, errorHandling ErrorHandling) *FlagSet {
+	f := &FlagSet{
+		name:          name,
+		errorHandling: errorHandling,
+	}
+	return f
+}
+
+// NewFlagSetWithEnvPrefix returns a new empty flag set with the specified name,
+// environment variable prefix, and error handling property.
+func NewFlagSetWithEnvPrefix(name string, prefix string, errorHandling ErrorHandling) *FlagSet {
+	f := NewFlagSet(name, errorHandling)
+	f.envPrefix = prefix
+	return f
+}
+
+// Init sets the name, environment name prefix, and error handling property
+// for a flag set.
+// By default, the zero FlagSet uses an empty name, EnvironmentPrefix, and the
+// ContinueOnError error handling policy.
+func (f *FlagSet) Init(name string, errorHandling ErrorHandling) {
+	f.name = name
+	f.envPrefix = EnvironmentPrefix
+	f.errorHandling = errorHandling
+}
diff --git a/vendor/gopkg.in/yaml.v2/.travis.yml b/vendor/gopkg.in/yaml.v2/.travis.yml
new file mode 100644
index 0000000..9f55693
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/.travis.yml
@@ -0,0 +1,12 @@
+language: go
+
+go:
+    - 1.4
+    - 1.5
+    - 1.6
+    - 1.7
+    - 1.8
+    - 1.9
+    - tip
+
+go_import_path: gopkg.in/yaml.v2
diff --git a/vendor/gopkg.in/yaml.v2/LICENSE b/vendor/gopkg.in/yaml.v2/LICENSE
new file mode 100644
index 0000000..8dada3e
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/LICENSE
@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright {yyyy} {name of copyright owner}
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/vendor/gopkg.in/yaml.v2/LICENSE.libyaml b/vendor/gopkg.in/yaml.v2/LICENSE.libyaml
new file mode 100644
index 0000000..8da58fb
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/LICENSE.libyaml
@@ -0,0 +1,31 @@
+The following files were ported to Go from C files of libyaml, and thus
+are still covered by their original copyright and license:
+
+    apic.go
+    emitterc.go
+    parserc.go
+    readerc.go
+    scannerc.go
+    writerc.go
+    yamlh.go
+    yamlprivateh.go
+
+Copyright (c) 2006 Kirill Simonov
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/vendor/gopkg.in/yaml.v2/NOTICE b/vendor/gopkg.in/yaml.v2/NOTICE
new file mode 100644
index 0000000..866d74a
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/NOTICE
@@ -0,0 +1,13 @@
+Copyright 2011-2016 Canonical Ltd.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
diff --git a/vendor/gopkg.in/yaml.v2/README.md b/vendor/gopkg.in/yaml.v2/README.md
new file mode 100644
index 0000000..b50c6e8
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/README.md
@@ -0,0 +1,133 @@
+# YAML support for the Go language
+
+Introduction
+------------
+
+The yaml package enables Go programs to comfortably encode and decode YAML
+values. It was developed within [Canonical](https://www.canonical.com) as
+part of the [juju](https://juju.ubuntu.com) project, and is based on a
+pure Go port of the well-known [libyaml](http://pyyaml.org/wiki/LibYAML)
+C library to parse and generate YAML data quickly and reliably.
+
+Compatibility
+-------------
+
+The yaml package supports most of YAML 1.1 and 1.2, including support for
+anchors, tags, map merging, etc. Multi-document unmarshalling is not yet
+implemented, and base-60 floats from YAML 1.1 are purposefully not
+supported since they're a poor design and are gone in YAML 1.2.
+
+Installation and usage
+----------------------
+
+The import path for the package is *gopkg.in/yaml.v2*.
+
+To install it, run:
+
+    go get gopkg.in/yaml.v2
+
+API documentation
+-----------------
+
+If opened in a browser, the import path itself leads to the API documentation:
+
+  * [https://gopkg.in/yaml.v2](https://gopkg.in/yaml.v2)
+
+API stability
+-------------
+
+The package API for yaml v2 will remain stable as described in [gopkg.in](https://gopkg.in).
+
+
+License
+-------
+
+The yaml package is licensed under the Apache License 2.0. Please see the LICENSE file for details.
+
+
+Example
+-------
+
+```Go
+package main
+
+import (
+        "fmt"
+        "log"
+
+        "gopkg.in/yaml.v2"
+)
+
+var data = `
+a: Easy!
+b:
+  c: 2
+  d: [3, 4]
+`
+
+// Note: struct fields must be public in order for unmarshal to
+// correctly populate the data.
+type T struct {
+        A string
+        B struct {
+                RenamedC int   `yaml:"c"`
+                D        []int `yaml:",flow"`
+        }
+}
+
+func main() {
+        t := T{}
+    
+        err := yaml.Unmarshal([]byte(data), &t)
+        if err != nil {
+                log.Fatalf("error: %v", err)
+        }
+        fmt.Printf("--- t:\n%v\n\n", t)
+    
+        d, err := yaml.Marshal(&t)
+        if err != nil {
+                log.Fatalf("error: %v", err)
+        }
+        fmt.Printf("--- t dump:\n%s\n\n", string(d))
+    
+        m := make(map[interface{}]interface{})
+    
+        err = yaml.Unmarshal([]byte(data), &m)
+        if err != nil {
+                log.Fatalf("error: %v", err)
+        }
+        fmt.Printf("--- m:\n%v\n\n", m)
+    
+        d, err = yaml.Marshal(&m)
+        if err != nil {
+                log.Fatalf("error: %v", err)
+        }
+        fmt.Printf("--- m dump:\n%s\n\n", string(d))
+}
+```
+
+This example will generate the following output:
+
+```
+--- t:
+{Easy! {2 [3 4]}}
+
+--- t dump:
+a: Easy!
+b:
+  c: 2
+  d: [3, 4]
+
+
+--- m:
+map[a:Easy! b:map[c:2 d:[3 4]]]
+
+--- m dump:
+a: Easy!
+b:
+  c: 2
+  d:
+  - 3
+  - 4
+```
+
diff --git a/vendor/gopkg.in/yaml.v2/apic.go b/vendor/gopkg.in/yaml.v2/apic.go
new file mode 100644
index 0000000..1f7e87e
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/apic.go
@@ -0,0 +1,739 @@
+package yaml
+
+import (
+	"io"
+)
+
+func yaml_insert_token(parser *yaml_parser_t, pos int, token *yaml_token_t) {
+	//fmt.Println("yaml_insert_token", "pos:", pos, "typ:", token.typ, "head:", parser.tokens_head, "len:", len(parser.tokens))
+
+	// Check if we can move the queue at the beginning of the buffer.
+	if parser.tokens_head > 0 && len(parser.tokens) == cap(parser.tokens) {
+		if parser.tokens_head != len(parser.tokens) {
+			copy(parser.tokens, parser.tokens[parser.tokens_head:])
+		}
+		parser.tokens = parser.tokens[:len(parser.tokens)-parser.tokens_head]
+		parser.tokens_head = 0
+	}
+	parser.tokens = append(parser.tokens, *token)
+	if pos < 0 {
+		return
+	}
+	copy(parser.tokens[parser.tokens_head+pos+1:], parser.tokens[parser.tokens_head+pos:])
+	parser.tokens[parser.tokens_head+pos] = *token
+}
+
+// Create a new parser object.
+func yaml_parser_initialize(parser *yaml_parser_t) bool {
+	*parser = yaml_parser_t{
+		raw_buffer: make([]byte, 0, input_raw_buffer_size),
+		buffer:     make([]byte, 0, input_buffer_size),
+	}
+	return true
+}
+
+// Destroy a parser object.
+func yaml_parser_delete(parser *yaml_parser_t) {
+	*parser = yaml_parser_t{}
+}
+
+// String read handler.
+func yaml_string_read_handler(parser *yaml_parser_t, buffer []byte) (n int, err error) {
+	if parser.input_pos == len(parser.input) {
+		return 0, io.EOF
+	}
+	n = copy(buffer, parser.input[parser.input_pos:])
+	parser.input_pos += n
+	return n, nil
+}
+
+// Reader read handler.
+func yaml_reader_read_handler(parser *yaml_parser_t, buffer []byte) (n int, err error) {
+	return parser.input_reader.Read(buffer)
+}
+
+// Set a string input.
+func yaml_parser_set_input_string(parser *yaml_parser_t, input []byte) {
+	if parser.read_handler != nil {
+		panic("must set the input source only once")
+	}
+	parser.read_handler = yaml_string_read_handler
+	parser.input = input
+	parser.input_pos = 0
+}
+
+// Set a file input.
+func yaml_parser_set_input_reader(parser *yaml_parser_t, r io.Reader) {
+	if parser.read_handler != nil {
+		panic("must set the input source only once")
+	}
+	parser.read_handler = yaml_reader_read_handler
+	parser.input_reader = r
+}
+
+// Set the source encoding.
+func yaml_parser_set_encoding(parser *yaml_parser_t, encoding yaml_encoding_t) {
+	if parser.encoding != yaml_ANY_ENCODING {
+		panic("must set the encoding only once")
+	}
+	parser.encoding = encoding
+}
+
+// Create a new emitter object.
+func yaml_emitter_initialize(emitter *yaml_emitter_t) {
+	*emitter = yaml_emitter_t{
+		buffer:     make([]byte, output_buffer_size),
+		raw_buffer: make([]byte, 0, output_raw_buffer_size),
+		states:     make([]yaml_emitter_state_t, 0, initial_stack_size),
+		events:     make([]yaml_event_t, 0, initial_queue_size),
+	}
+}
+
+// Destroy an emitter object.
+func yaml_emitter_delete(emitter *yaml_emitter_t) {
+	*emitter = yaml_emitter_t{}
+}
+
+// String write handler.
+func yaml_string_write_handler(emitter *yaml_emitter_t, buffer []byte) error {
+	*emitter.output_buffer = append(*emitter.output_buffer, buffer...)
+	return nil
+}
+
+// yaml_writer_write_handler uses emitter.output_writer to write the
+// emitted text.
+func yaml_writer_write_handler(emitter *yaml_emitter_t, buffer []byte) error {
+	_, err := emitter.output_writer.Write(buffer)
+	return err
+}
+
+// Set a string output.
+func yaml_emitter_set_output_string(emitter *yaml_emitter_t, output_buffer *[]byte) {
+	if emitter.write_handler != nil {
+		panic("must set the output target only once")
+	}
+	emitter.write_handler = yaml_string_write_handler
+	emitter.output_buffer = output_buffer
+}
+
+// Set a file output.
+func yaml_emitter_set_output_writer(emitter *yaml_emitter_t, w io.Writer) {
+	if emitter.write_handler != nil {
+		panic("must set the output target only once")
+	}
+	emitter.write_handler = yaml_writer_write_handler
+	emitter.output_writer = w
+}
+
+// Set the output encoding.
+func yaml_emitter_set_encoding(emitter *yaml_emitter_t, encoding yaml_encoding_t) {
+	if emitter.encoding != yaml_ANY_ENCODING {
+		panic("must set the output encoding only once")
+	}
+	emitter.encoding = encoding
+}
+
+// Set the canonical output style.
+func yaml_emitter_set_canonical(emitter *yaml_emitter_t, canonical bool) {
+	emitter.canonical = canonical
+}
+
+//// Set the indentation increment.
+func yaml_emitter_set_indent(emitter *yaml_emitter_t, indent int) {
+	if indent < 2 || indent > 9 {
+		indent = 2
+	}
+	emitter.best_indent = indent
+}
+
+// Set the preferred line width.
+func yaml_emitter_set_width(emitter *yaml_emitter_t, width int) {
+	if width < 0 {
+		width = -1
+	}
+	emitter.best_width = width
+}
+
+// Set if unescaped non-ASCII characters are allowed.
+func yaml_emitter_set_unicode(emitter *yaml_emitter_t, unicode bool) {
+	emitter.unicode = unicode
+}
+
+// Set the preferred line break character.
+func yaml_emitter_set_break(emitter *yaml_emitter_t, line_break yaml_break_t) {
+	emitter.line_break = line_break
+}
+
+///*
+// * Destroy a token object.
+// */
+//
+//YAML_DECLARE(void)
+//yaml_token_delete(yaml_token_t *token)
+//{
+//    assert(token);  // Non-NULL token object expected.
+//
+//    switch (token.type)
+//    {
+//        case YAML_TAG_DIRECTIVE_TOKEN:
+//            yaml_free(token.data.tag_directive.handle);
+//            yaml_free(token.data.tag_directive.prefix);
+//            break;
+//
+//        case YAML_ALIAS_TOKEN:
+//            yaml_free(token.data.alias.value);
+//            break;
+//
+//        case YAML_ANCHOR_TOKEN:
+//            yaml_free(token.data.anchor.value);
+//            break;
+//
+//        case YAML_TAG_TOKEN:
+//            yaml_free(token.data.tag.handle);
+//            yaml_free(token.data.tag.suffix);
+//            break;
+//
+//        case YAML_SCALAR_TOKEN:
+//            yaml_free(token.data.scalar.value);
+//            break;
+//
+//        default:
+//            break;
+//    }
+//
+//    memset(token, 0, sizeof(yaml_token_t));
+//}
+//
+///*
+// * Check if a string is a valid UTF-8 sequence.
+// *
+// * Check 'reader.c' for more details on UTF-8 encoding.
+// */
+//
+//static int
+//yaml_check_utf8(yaml_char_t *start, size_t length)
+//{
+//    yaml_char_t *end = start+length;
+//    yaml_char_t *pointer = start;
+//
+//    while (pointer < end) {
+//        unsigned char octet;
+//        unsigned int width;
+//        unsigned int value;
+//        size_t k;
+//
+//        octet = pointer[0];
+//        width = (octet & 0x80) == 0x00 ? 1 :
+//                (octet & 0xE0) == 0xC0 ? 2 :
+//                (octet & 0xF0) == 0xE0 ? 3 :
+//                (octet & 0xF8) == 0xF0 ? 4 : 0;
+//        value = (octet & 0x80) == 0x00 ? octet & 0x7F :
+//                (octet & 0xE0) == 0xC0 ? octet & 0x1F :
+//                (octet & 0xF0) == 0xE0 ? octet & 0x0F :
+//                (octet & 0xF8) == 0xF0 ? octet & 0x07 : 0;
+//        if (!width) return 0;
+//        if (pointer+width > end) return 0;
+//        for (k = 1; k < width; k ++) {
+//            octet = pointer[k];
+//            if ((octet & 0xC0) != 0x80) return 0;
+//            value = (value << 6) + (octet & 0x3F);
+//        }
+//        if (!((width == 1) ||
+//            (width == 2 && value >= 0x80) ||
+//            (width == 3 && value >= 0x800) ||
+//            (width == 4 && value >= 0x10000))) return 0;
+//
+//        pointer += width;
+//    }
+//
+//    return 1;
+//}
+//
+
+// Create STREAM-START.
+func yaml_stream_start_event_initialize(event *yaml_event_t, encoding yaml_encoding_t) {
+	*event = yaml_event_t{
+		typ:      yaml_STREAM_START_EVENT,
+		encoding: encoding,
+	}
+}
+
+// Create STREAM-END.
+func yaml_stream_end_event_initialize(event *yaml_event_t) {
+	*event = yaml_event_t{
+		typ: yaml_STREAM_END_EVENT,
+	}
+}
+
+// Create DOCUMENT-START.
+func yaml_document_start_event_initialize(
+	event *yaml_event_t,
+	version_directive *yaml_version_directive_t,
+	tag_directives []yaml_tag_directive_t,
+	implicit bool,
+) {
+	*event = yaml_event_t{
+		typ:               yaml_DOCUMENT_START_EVENT,
+		version_directive: version_directive,
+		tag_directives:    tag_directives,
+		implicit:          implicit,
+	}
+}
+
+// Create DOCUMENT-END.
+func yaml_document_end_event_initialize(event *yaml_event_t, implicit bool) {
+	*event = yaml_event_t{
+		typ:      yaml_DOCUMENT_END_EVENT,
+		implicit: implicit,
+	}
+}
+
+///*
+// * Create ALIAS.
+// */
+//
+//YAML_DECLARE(int)
+//yaml_alias_event_initialize(event *yaml_event_t, anchor *yaml_char_t)
+//{
+//    mark yaml_mark_t = { 0, 0, 0 }
+//    anchor_copy *yaml_char_t = NULL
+//
+//    assert(event) // Non-NULL event object is expected.
+//    assert(anchor) // Non-NULL anchor is expected.
+//
+//    if (!yaml_check_utf8(anchor, strlen((char *)anchor))) return 0
+//
+//    anchor_copy = yaml_strdup(anchor)
+//    if (!anchor_copy)
+//        return 0
+//
+//    ALIAS_EVENT_INIT(*event, anchor_copy, mark, mark)
+//
+//    return 1
+//}
+
+// Create SCALAR.
+func yaml_scalar_event_initialize(event *yaml_event_t, anchor, tag, value []byte, plain_implicit, quoted_implicit bool, style yaml_scalar_style_t) bool {
+	*event = yaml_event_t{
+		typ:             yaml_SCALAR_EVENT,
+		anchor:          anchor,
+		tag:             tag,
+		value:           value,
+		implicit:        plain_implicit,
+		quoted_implicit: quoted_implicit,
+		style:           yaml_style_t(style),
+	}
+	return true
+}
+
+// Create SEQUENCE-START.
+func yaml_sequence_start_event_initialize(event *yaml_event_t, anchor, tag []byte, implicit bool, style yaml_sequence_style_t) bool {
+	*event = yaml_event_t{
+		typ:      yaml_SEQUENCE_START_EVENT,
+		anchor:   anchor,
+		tag:      tag,
+		implicit: implicit,
+		style:    yaml_style_t(style),
+	}
+	return true
+}
+
+// Create SEQUENCE-END.
+func yaml_sequence_end_event_initialize(event *yaml_event_t) bool {
+	*event = yaml_event_t{
+		typ: yaml_SEQUENCE_END_EVENT,
+	}
+	return true
+}
+
+// Create MAPPING-START.
+func yaml_mapping_start_event_initialize(event *yaml_event_t, anchor, tag []byte, implicit bool, style yaml_mapping_style_t) {
+	*event = yaml_event_t{
+		typ:      yaml_MAPPING_START_EVENT,
+		anchor:   anchor,
+		tag:      tag,
+		implicit: implicit,
+		style:    yaml_style_t(style),
+	}
+}
+
+// Create MAPPING-END.
+func yaml_mapping_end_event_initialize(event *yaml_event_t) {
+	*event = yaml_event_t{
+		typ: yaml_MAPPING_END_EVENT,
+	}
+}
+
+// Destroy an event object.
+func yaml_event_delete(event *yaml_event_t) {
+	*event = yaml_event_t{}
+}
+
+///*
+// * Create a document object.
+// */
+//
+//YAML_DECLARE(int)
+//yaml_document_initialize(document *yaml_document_t,
+//        version_directive *yaml_version_directive_t,
+//        tag_directives_start *yaml_tag_directive_t,
+//        tag_directives_end *yaml_tag_directive_t,
+//        start_implicit int, end_implicit int)
+//{
+//    struct {
+//        error yaml_error_type_t
+//    } context
+//    struct {
+//        start *yaml_node_t
+//        end *yaml_node_t
+//        top *yaml_node_t
+//    } nodes = { NULL, NULL, NULL }
+//    version_directive_copy *yaml_version_directive_t = NULL
+//    struct {
+//        start *yaml_tag_directive_t
+//        end *yaml_tag_directive_t
+//        top *yaml_tag_directive_t
+//    } tag_directives_copy = { NULL, NULL, NULL }
+//    value yaml_tag_directive_t = { NULL, NULL }
+//    mark yaml_mark_t = { 0, 0, 0 }
+//
+//    assert(document) // Non-NULL document object is expected.
+//    assert((tag_directives_start && tag_directives_end) ||
+//            (tag_directives_start == tag_directives_end))
+//                            // Valid tag directives are expected.
+//
+//    if (!STACK_INIT(&context, nodes, INITIAL_STACK_SIZE)) goto error
+//
+//    if (version_directive) {
+//        version_directive_copy = yaml_malloc(sizeof(yaml_version_directive_t))
+//        if (!version_directive_copy) goto error
+//        version_directive_copy.major = version_directive.major
+//        version_directive_copy.minor = version_directive.minor
+//    }
+//
+//    if (tag_directives_start != tag_directives_end) {
+//        tag_directive *yaml_tag_directive_t
+//        if (!STACK_INIT(&context, tag_directives_copy, INITIAL_STACK_SIZE))
+//            goto error
+//        for (tag_directive = tag_directives_start
+//                tag_directive != tag_directives_end; tag_directive ++) {
+//            assert(tag_directive.handle)
+//            assert(tag_directive.prefix)
+//            if (!yaml_check_utf8(tag_directive.handle,
+//                        strlen((char *)tag_directive.handle)))
+//                goto error
+//            if (!yaml_check_utf8(tag_directive.prefix,
+//                        strlen((char *)tag_directive.prefix)))
+//                goto error
+//            value.handle = yaml_strdup(tag_directive.handle)
+//            value.prefix = yaml_strdup(tag_directive.prefix)
+//            if (!value.handle || !value.prefix) goto error
+//            if (!PUSH(&context, tag_directives_copy, value))
+//                goto error
+//            value.handle = NULL
+//            value.prefix = NULL
+//        }
+//    }
+//
+//    DOCUMENT_INIT(*document, nodes.start, nodes.end, version_directive_copy,
+//            tag_directives_copy.start, tag_directives_copy.top,
+//            start_implicit, end_implicit, mark, mark)
+//
+//    return 1
+//
+//error:
+//    STACK_DEL(&context, nodes)
+//    yaml_free(version_directive_copy)
+//    while (!STACK_EMPTY(&context, tag_directives_copy)) {
+//        value yaml_tag_directive_t = POP(&context, tag_directives_copy)
+//        yaml_free(value.handle)
+//        yaml_free(value.prefix)
+//    }
+//    STACK_DEL(&context, tag_directives_copy)
+//    yaml_free(value.handle)
+//    yaml_free(value.prefix)
+//
+//    return 0
+//}
+//
+///*
+// * Destroy a document object.
+// */
+//
+//YAML_DECLARE(void)
+//yaml_document_delete(document *yaml_document_t)
+//{
+//    struct {
+//        error yaml_error_type_t
+//    } context
+//    tag_directive *yaml_tag_directive_t
+//
+//    context.error = YAML_NO_ERROR // Eliminate a compiler warning.
+//
+//    assert(document) // Non-NULL document object is expected.
+//
+//    while (!STACK_EMPTY(&context, document.nodes)) {
+//        node yaml_node_t = POP(&context, document.nodes)
+//        yaml_free(node.tag)
+//        switch (node.type) {
+//            case YAML_SCALAR_NODE:
+//                yaml_free(node.data.scalar.value)
+//                break
+//            case YAML_SEQUENCE_NODE:
+//                STACK_DEL(&context, node.data.sequence.items)
+//                break
+//            case YAML_MAPPING_NODE:
+//                STACK_DEL(&context, node.data.mapping.pairs)
+//                break
+//            default:
+//                assert(0) // Should not happen.
+//        }
+//    }
+//    STACK_DEL(&context, document.nodes)
+//
+//    yaml_free(document.version_directive)
+//    for (tag_directive = document.tag_directives.start
+//            tag_directive != document.tag_directives.end
+//            tag_directive++) {
+//        yaml_free(tag_directive.handle)
+//        yaml_free(tag_directive.prefix)
+//    }
+//    yaml_free(document.tag_directives.start)
+//
+//    memset(document, 0, sizeof(yaml_document_t))
+//}
+//
+///**
+// * Get a document node.
+// */
+//
+//YAML_DECLARE(yaml_node_t *)
+//yaml_document_get_node(document *yaml_document_t, index int)
+//{
+//    assert(document) // Non-NULL document object is expected.
+//
+//    if (index > 0 && document.nodes.start + index <= document.nodes.top) {
+//        return document.nodes.start + index - 1
+//    }
+//    return NULL
+//}
+//
+///**
+// * Get the root object.
+// */
+//
+//YAML_DECLARE(yaml_node_t *)
+//yaml_document_get_root_node(document *yaml_document_t)
+//{
+//    assert(document) // Non-NULL document object is expected.
+//
+//    if (document.nodes.top != document.nodes.start) {
+//        return document.nodes.start
+//    }
+//    return NULL
+//}
+//
+///*
+// * Add a scalar node to a document.
+// */
+//
+//YAML_DECLARE(int)
+//yaml_document_add_scalar(document *yaml_document_t,
+//        tag *yaml_char_t, value *yaml_char_t, length int,
+//        style yaml_scalar_style_t)
+//{
+//    struct {
+//        error yaml_error_type_t
+//    } context
+//    mark yaml_mark_t = { 0, 0, 0 }
+//    tag_copy *yaml_char_t = NULL
+//    value_copy *yaml_char_t = NULL
+//    node yaml_node_t
+//
+//    assert(document) // Non-NULL document object is expected.
+//    assert(value) // Non-NULL value is expected.
+//
+//    if (!tag) {
+//        tag = (yaml_char_t *)YAML_DEFAULT_SCALAR_TAG
+//    }
+//
+//    if (!yaml_check_utf8(tag, strlen((char *)tag))) goto error
+//    tag_copy = yaml_strdup(tag)
+//    if (!tag_copy) goto error
+//
+//    if (length < 0) {
+//        length = strlen((char *)value)
+//    }
+//
+//    if (!yaml_check_utf8(value, length)) goto error
+//    value_copy = yaml_malloc(length+1)
+//    if (!value_copy) goto error
+//    memcpy(value_copy, value, length)
+//    value_copy[length] = '\0'
+//
+//    SCALAR_NODE_INIT(node, tag_copy, value_copy, length, style, mark, mark)
+//    if (!PUSH(&context, document.nodes, node)) goto error
+//
+//    return document.nodes.top - document.nodes.start
+//
+//error:
+//    yaml_free(tag_copy)
+//    yaml_free(value_copy)
+//
+//    return 0
+//}
+//
+///*
+// * Add a sequence node to a document.
+// */
+//
+//YAML_DECLARE(int)
+//yaml_document_add_sequence(document *yaml_document_t,
+//        tag *yaml_char_t, style yaml_sequence_style_t)
+//{
+//    struct {
+//        error yaml_error_type_t
+//    } context
+//    mark yaml_mark_t = { 0, 0, 0 }
+//    tag_copy *yaml_char_t = NULL
+//    struct {
+//        start *yaml_node_item_t
+//        end *yaml_node_item_t
+//        top *yaml_node_item_t
+//    } items = { NULL, NULL, NULL }
+//    node yaml_node_t
+//
+//    assert(document) // Non-NULL document object is expected.
+//
+//    if (!tag) {
+//        tag = (yaml_char_t *)YAML_DEFAULT_SEQUENCE_TAG
+//    }
+//
+//    if (!yaml_check_utf8(tag, strlen((char *)tag))) goto error
+//    tag_copy = yaml_strdup(tag)
+//    if (!tag_copy) goto error
+//
+//    if (!STACK_INIT(&context, items, INITIAL_STACK_SIZE)) goto error
+//
+//    SEQUENCE_NODE_INIT(node, tag_copy, items.start, items.end,
+//            style, mark, mark)
+//    if (!PUSH(&context, document.nodes, node)) goto error
+//
+//    return document.nodes.top - document.nodes.start
+//
+//error:
+//    STACK_DEL(&context, items)
+//    yaml_free(tag_copy)
+//
+//    return 0
+//}
+//
+///*
+// * Add a mapping node to a document.
+// */
+//
+//YAML_DECLARE(int)
+//yaml_document_add_mapping(document *yaml_document_t,
+//        tag *yaml_char_t, style yaml_mapping_style_t)
+//{
+//    struct {
+//        error yaml_error_type_t
+//    } context
+//    mark yaml_mark_t = { 0, 0, 0 }
+//    tag_copy *yaml_char_t = NULL
+//    struct {
+//        start *yaml_node_pair_t
+//        end *yaml_node_pair_t
+//        top *yaml_node_pair_t
+//    } pairs = { NULL, NULL, NULL }
+//    node yaml_node_t
+//
+//    assert(document) // Non-NULL document object is expected.
+//
+//    if (!tag) {
+//        tag = (yaml_char_t *)YAML_DEFAULT_MAPPING_TAG
+//    }
+//
+//    if (!yaml_check_utf8(tag, strlen((char *)tag))) goto error
+//    tag_copy = yaml_strdup(tag)
+//    if (!tag_copy) goto error
+//
+//    if (!STACK_INIT(&context, pairs, INITIAL_STACK_SIZE)) goto error
+//
+//    MAPPING_NODE_INIT(node, tag_copy, pairs.start, pairs.end,
+//            style, mark, mark)
+//    if (!PUSH(&context, document.nodes, node)) goto error
+//
+//    return document.nodes.top - document.nodes.start
+//
+//error:
+//    STACK_DEL(&context, pairs)
+//    yaml_free(tag_copy)
+//
+//    return 0
+//}
+//
+///*
+// * Append an item to a sequence node.
+// */
+//
+//YAML_DECLARE(int)
+//yaml_document_append_sequence_item(document *yaml_document_t,
+//        sequence int, item int)
+//{
+//    struct {
+//        error yaml_error_type_t
+//    } context
+//
+//    assert(document) // Non-NULL document is required.
+//    assert(sequence > 0
+//            && document.nodes.start + sequence <= document.nodes.top)
+//                            // Valid sequence id is required.
+//    assert(document.nodes.start[sequence-1].type == YAML_SEQUENCE_NODE)
+//                            // A sequence node is required.
+//    assert(item > 0 && document.nodes.start + item <= document.nodes.top)
+//                            // Valid item id is required.
+//
+//    if (!PUSH(&context,
+//                document.nodes.start[sequence-1].data.sequence.items, item))
+//        return 0
+//
+//    return 1
+//}
+//
+///*
+// * Append a pair of a key and a value to a mapping node.
+// */
+//
+//YAML_DECLARE(int)
+//yaml_document_append_mapping_pair(document *yaml_document_t,
+//        mapping int, key int, value int)
+//{
+//    struct {
+//        error yaml_error_type_t
+//    } context
+//
+//    pair yaml_node_pair_t
+//
+//    assert(document) // Non-NULL document is required.
+//    assert(mapping > 0
+//            && document.nodes.start + mapping <= document.nodes.top)
+//                            // Valid mapping id is required.
+//    assert(document.nodes.start[mapping-1].type == YAML_MAPPING_NODE)
+//                            // A mapping node is required.
+//    assert(key > 0 && document.nodes.start + key <= document.nodes.top)
+//                            // Valid key id is required.
+//    assert(value > 0 && document.nodes.start + value <= document.nodes.top)
+//                            // Valid value id is required.
+//
+//    pair.key = key
+//    pair.value = value
+//
+//    if (!PUSH(&context,
+//                document.nodes.start[mapping-1].data.mapping.pairs, pair))
+//        return 0
+//
+//    return 1
+//}
+//
+//
diff --git a/vendor/gopkg.in/yaml.v2/decode.go b/vendor/gopkg.in/yaml.v2/decode.go
new file mode 100644
index 0000000..e4e56e2
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/decode.go
@@ -0,0 +1,775 @@
+package yaml
+
+import (
+	"encoding"
+	"encoding/base64"
+	"fmt"
+	"io"
+	"math"
+	"reflect"
+	"strconv"
+	"time"
+)
+
+const (
+	documentNode = 1 << iota
+	mappingNode
+	sequenceNode
+	scalarNode
+	aliasNode
+)
+
+type node struct {
+	kind         int
+	line, column int
+	tag          string
+	// For an alias node, alias holds the resolved alias.
+	alias    *node
+	value    string
+	implicit bool
+	children []*node
+	anchors  map[string]*node
+}
+
+// ----------------------------------------------------------------------------
+// Parser, produces a node tree out of a libyaml event stream.
+
+type parser struct {
+	parser   yaml_parser_t
+	event    yaml_event_t
+	doc      *node
+	doneInit bool
+}
+
+func newParser(b []byte) *parser {
+	p := parser{}
+	if !yaml_parser_initialize(&p.parser) {
+		panic("failed to initialize YAML emitter")
+	}
+	if len(b) == 0 {
+		b = []byte{'\n'}
+	}
+	yaml_parser_set_input_string(&p.parser, b)
+	return &p
+}
+
+func newParserFromReader(r io.Reader) *parser {
+	p := parser{}
+	if !yaml_parser_initialize(&p.parser) {
+		panic("failed to initialize YAML emitter")
+	}
+	yaml_parser_set_input_reader(&p.parser, r)
+	return &p
+}
+
+func (p *parser) init() {
+	if p.doneInit {
+		return
+	}
+	p.expect(yaml_STREAM_START_EVENT)
+	p.doneInit = true
+}
+
+func (p *parser) destroy() {
+	if p.event.typ != yaml_NO_EVENT {
+		yaml_event_delete(&p.event)
+	}
+	yaml_parser_delete(&p.parser)
+}
+
+// expect consumes an event from the event stream and
+// checks that it's of the expected type.
+func (p *parser) expect(e yaml_event_type_t) {
+	if p.event.typ == yaml_NO_EVENT {
+		if !yaml_parser_parse(&p.parser, &p.event) {
+			p.fail()
+		}
+	}
+	if p.event.typ == yaml_STREAM_END_EVENT {
+		failf("attempted to go past the end of stream; corrupted value?")
+	}
+	if p.event.typ != e {
+		p.parser.problem = fmt.Sprintf("expected %s event but got %s", e, p.event.typ)
+		p.fail()
+	}
+	yaml_event_delete(&p.event)
+	p.event.typ = yaml_NO_EVENT
+}
+
+// peek peeks at the next event in the event stream,
+// puts the results into p.event and returns the event type.
+func (p *parser) peek() yaml_event_type_t {
+	if p.event.typ != yaml_NO_EVENT {
+		return p.event.typ
+	}
+	if !yaml_parser_parse(&p.parser, &p.event) {
+		p.fail()
+	}
+	return p.event.typ
+}
+
+func (p *parser) fail() {
+	var where string
+	var line int
+	if p.parser.problem_mark.line != 0 {
+		line = p.parser.problem_mark.line
+		// Scanner errors don't iterate line before returning error
+		if p.parser.error == yaml_SCANNER_ERROR {
+			line++
+		}
+	} else if p.parser.context_mark.line != 0 {
+		line = p.parser.context_mark.line
+	}
+	if line != 0 {
+		where = "line " + strconv.Itoa(line) + ": "
+	}
+	var msg string
+	if len(p.parser.problem) > 0 {
+		msg = p.parser.problem
+	} else {
+		msg = "unknown problem parsing YAML content"
+	}
+	failf("%s%s", where, msg)
+}
+
+func (p *parser) anchor(n *node, anchor []byte) {
+	if anchor != nil {
+		p.doc.anchors[string(anchor)] = n
+	}
+}
+
+func (p *parser) parse() *node {
+	p.init()
+	switch p.peek() {
+	case yaml_SCALAR_EVENT:
+		return p.scalar()
+	case yaml_ALIAS_EVENT:
+		return p.alias()
+	case yaml_MAPPING_START_EVENT:
+		return p.mapping()
+	case yaml_SEQUENCE_START_EVENT:
+		return p.sequence()
+	case yaml_DOCUMENT_START_EVENT:
+		return p.document()
+	case yaml_STREAM_END_EVENT:
+		// Happens when attempting to decode an empty buffer.
+		return nil
+	default:
+		panic("attempted to parse unknown event: " + p.event.typ.String())
+	}
+}
+
+func (p *parser) node(kind int) *node {
+	return &node{
+		kind:   kind,
+		line:   p.event.start_mark.line,
+		column: p.event.start_mark.column,
+	}
+}
+
+func (p *parser) document() *node {
+	n := p.node(documentNode)
+	n.anchors = make(map[string]*node)
+	p.doc = n
+	p.expect(yaml_DOCUMENT_START_EVENT)
+	n.children = append(n.children, p.parse())
+	p.expect(yaml_DOCUMENT_END_EVENT)
+	return n
+}
+
+func (p *parser) alias() *node {
+	n := p.node(aliasNode)
+	n.value = string(p.event.anchor)
+	n.alias = p.doc.anchors[n.value]
+	if n.alias == nil {
+		failf("unknown anchor '%s' referenced", n.value)
+	}
+	p.expect(yaml_ALIAS_EVENT)
+	return n
+}
+
+func (p *parser) scalar() *node {
+	n := p.node(scalarNode)
+	n.value = string(p.event.value)
+	n.tag = string(p.event.tag)
+	n.implicit = p.event.implicit
+	p.anchor(n, p.event.anchor)
+	p.expect(yaml_SCALAR_EVENT)
+	return n
+}
+
+func (p *parser) sequence() *node {
+	n := p.node(sequenceNode)
+	p.anchor(n, p.event.anchor)
+	p.expect(yaml_SEQUENCE_START_EVENT)
+	for p.peek() != yaml_SEQUENCE_END_EVENT {
+		n.children = append(n.children, p.parse())
+	}
+	p.expect(yaml_SEQUENCE_END_EVENT)
+	return n
+}
+
+func (p *parser) mapping() *node {
+	n := p.node(mappingNode)
+	p.anchor(n, p.event.anchor)
+	p.expect(yaml_MAPPING_START_EVENT)
+	for p.peek() != yaml_MAPPING_END_EVENT {
+		n.children = append(n.children, p.parse(), p.parse())
+	}
+	p.expect(yaml_MAPPING_END_EVENT)
+	return n
+}
+
+// ----------------------------------------------------------------------------
+// Decoder, unmarshals a node into a provided value.
+
+type decoder struct {
+	doc     *node
+	aliases map[*node]bool
+	mapType reflect.Type
+	terrors []string
+	strict  bool
+}
+
+var (
+	mapItemType    = reflect.TypeOf(MapItem{})
+	durationType   = reflect.TypeOf(time.Duration(0))
+	defaultMapType = reflect.TypeOf(map[interface{}]interface{}{})
+	ifaceType      = defaultMapType.Elem()
+	timeType       = reflect.TypeOf(time.Time{})
+	ptrTimeType    = reflect.TypeOf(&time.Time{})
+)
+
+func newDecoder(strict bool) *decoder {
+	d := &decoder{mapType: defaultMapType, strict: strict}
+	d.aliases = make(map[*node]bool)
+	return d
+}
+
+func (d *decoder) terror(n *node, tag string, out reflect.Value) {
+	if n.tag != "" {
+		tag = n.tag
+	}
+	value := n.value
+	if tag != yaml_SEQ_TAG && tag != yaml_MAP_TAG {
+		if len(value) > 10 {
+			value = " `" + value[:7] + "...`"
+		} else {
+			value = " `" + value + "`"
+		}
+	}
+	d.terrors = append(d.terrors, fmt.Sprintf("line %d: cannot unmarshal %s%s into %s", n.line+1, shortTag(tag), value, out.Type()))
+}
+
+func (d *decoder) callUnmarshaler(n *node, u Unmarshaler) (good bool) {
+	terrlen := len(d.terrors)
+	err := u.UnmarshalYAML(func(v interface{}) (err error) {
+		defer handleErr(&err)
+		d.unmarshal(n, reflect.ValueOf(v))
+		if len(d.terrors) > terrlen {
+			issues := d.terrors[terrlen:]
+			d.terrors = d.terrors[:terrlen]
+			return &TypeError{issues}
+		}
+		return nil
+	})
+	if e, ok := err.(*TypeError); ok {
+		d.terrors = append(d.terrors, e.Errors...)
+		return false
+	}
+	if err != nil {
+		fail(err)
+	}
+	return true
+}
+
+// d.prepare initializes and dereferences pointers and calls UnmarshalYAML
+// if a value is found to implement it.
+// It returns the initialized and dereferenced out value, whether
+// unmarshalling was already done by UnmarshalYAML, and if so whether
+// its types unmarshalled appropriately.
+//
+// If n holds a null value, prepare returns before doing anything.
+func (d *decoder) prepare(n *node, out reflect.Value) (newout reflect.Value, unmarshaled, good bool) {
+	if n.tag == yaml_NULL_TAG || n.kind == scalarNode && n.tag == "" && (n.value == "null" || n.value == "~" || n.value == "" && n.implicit) {
+		return out, false, false
+	}
+	again := true
+	for again {
+		again = false
+		if out.Kind() == reflect.Ptr {
+			if out.IsNil() {
+				out.Set(reflect.New(out.Type().Elem()))
+			}
+			out = out.Elem()
+			again = true
+		}
+		if out.CanAddr() {
+			if u, ok := out.Addr().Interface().(Unmarshaler); ok {
+				good = d.callUnmarshaler(n, u)
+				return out, true, good
+			}
+		}
+	}
+	return out, false, false
+}
+
+func (d *decoder) unmarshal(n *node, out reflect.Value) (good bool) {
+	switch n.kind {
+	case documentNode:
+		return d.document(n, out)
+	case aliasNode:
+		return d.alias(n, out)
+	}
+	out, unmarshaled, good := d.prepare(n, out)
+	if unmarshaled {
+		return good
+	}
+	switch n.kind {
+	case scalarNode:
+		good = d.scalar(n, out)
+	case mappingNode:
+		good = d.mapping(n, out)
+	case sequenceNode:
+		good = d.sequence(n, out)
+	default:
+		panic("internal error: unknown node kind: " + strconv.Itoa(n.kind))
+	}
+	return good
+}
+
+func (d *decoder) document(n *node, out reflect.Value) (good bool) {
+	if len(n.children) == 1 {
+		d.doc = n
+		d.unmarshal(n.children[0], out)
+		return true
+	}
+	return false
+}
+
+func (d *decoder) alias(n *node, out reflect.Value) (good bool) {
+	if d.aliases[n] {
+		// TODO this could actually be allowed in some circumstances.
+		failf("anchor '%s' value contains itself", n.value)
+	}
+	d.aliases[n] = true
+	good = d.unmarshal(n.alias, out)
+	delete(d.aliases, n)
+	return good
+}
+
+var zeroValue reflect.Value
+
+func resetMap(out reflect.Value) {
+	for _, k := range out.MapKeys() {
+		out.SetMapIndex(k, zeroValue)
+	}
+}
+
+func (d *decoder) scalar(n *node, out reflect.Value) bool {
+	var tag string
+	var resolved interface{}
+	if n.tag == "" && !n.implicit {
+		tag = yaml_STR_TAG
+		resolved = n.value
+	} else {
+		tag, resolved = resolve(n.tag, n.value)
+		if tag == yaml_BINARY_TAG {
+			data, err := base64.StdEncoding.DecodeString(resolved.(string))
+			if err != nil {
+				failf("!!binary value contains invalid base64 data")
+			}
+			resolved = string(data)
+		}
+	}
+	if resolved == nil {
+		if out.Kind() == reflect.Map && !out.CanAddr() {
+			resetMap(out)
+		} else {
+			out.Set(reflect.Zero(out.Type()))
+		}
+		return true
+	}
+	if resolvedv := reflect.ValueOf(resolved); out.Type() == resolvedv.Type() {
+		// We've resolved to exactly the type we want, so use that.
+		out.Set(resolvedv)
+		return true
+	}
+	// Perhaps we can use the value as a TextUnmarshaler to
+	// set its value.
+	if out.CanAddr() {
+		u, ok := out.Addr().Interface().(encoding.TextUnmarshaler)
+		if ok {
+			var text []byte
+			if tag == yaml_BINARY_TAG {
+				text = []byte(resolved.(string))
+			} else {
+				// We let any value be unmarshaled into TextUnmarshaler.
+				// That might be more lax than we'd like, but the
+				// TextUnmarshaler itself should bowl out any dubious values.
+				text = []byte(n.value)
+			}
+			err := u.UnmarshalText(text)
+			if err != nil {
+				fail(err)
+			}
+			return true
+		}
+	}
+	switch out.Kind() {
+	case reflect.String:
+		if tag == yaml_BINARY_TAG {
+			out.SetString(resolved.(string))
+			return true
+		}
+		if resolved != nil {
+			out.SetString(n.value)
+			return true
+		}
+	case reflect.Interface:
+		if resolved == nil {
+			out.Set(reflect.Zero(out.Type()))
+		} else if tag == yaml_TIMESTAMP_TAG {
+			// It looks like a timestamp but for backward compatibility
+			// reasons we set it as a string, so that code that unmarshals
+			// timestamp-like values into interface{} will continue to
+			// see a string and not a time.Time.
+			// TODO(v3) Drop this.
+			out.Set(reflect.ValueOf(n.value))
+		} else {
+			out.Set(reflect.ValueOf(resolved))
+		}
+		return true
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		switch resolved := resolved.(type) {
+		case int:
+			if !out.OverflowInt(int64(resolved)) {
+				out.SetInt(int64(resolved))
+				return true
+			}
+		case int64:
+			if !out.OverflowInt(resolved) {
+				out.SetInt(resolved)
+				return true
+			}
+		case uint64:
+			if resolved <= math.MaxInt64 && !out.OverflowInt(int64(resolved)) {
+				out.SetInt(int64(resolved))
+				return true
+			}
+		case float64:
+			if resolved <= math.MaxInt64 && !out.OverflowInt(int64(resolved)) {
+				out.SetInt(int64(resolved))
+				return true
+			}
+		case string:
+			if out.Type() == durationType {
+				d, err := time.ParseDuration(resolved)
+				if err == nil {
+					out.SetInt(int64(d))
+					return true
+				}
+			}
+		}
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		switch resolved := resolved.(type) {
+		case int:
+			if resolved >= 0 && !out.OverflowUint(uint64(resolved)) {
+				out.SetUint(uint64(resolved))
+				return true
+			}
+		case int64:
+			if resolved >= 0 && !out.OverflowUint(uint64(resolved)) {
+				out.SetUint(uint64(resolved))
+				return true
+			}
+		case uint64:
+			if !out.OverflowUint(uint64(resolved)) {
+				out.SetUint(uint64(resolved))
+				return true
+			}
+		case float64:
+			if resolved <= math.MaxUint64 && !out.OverflowUint(uint64(resolved)) {
+				out.SetUint(uint64(resolved))
+				return true
+			}
+		}
+	case reflect.Bool:
+		switch resolved := resolved.(type) {
+		case bool:
+			out.SetBool(resolved)
+			return true
+		}
+	case reflect.Float32, reflect.Float64:
+		switch resolved := resolved.(type) {
+		case int:
+			out.SetFloat(float64(resolved))
+			return true
+		case int64:
+			out.SetFloat(float64(resolved))
+			return true
+		case uint64:
+			out.SetFloat(float64(resolved))
+			return true
+		case float64:
+			out.SetFloat(resolved)
+			return true
+		}
+	case reflect.Struct:
+		if resolvedv := reflect.ValueOf(resolved); out.Type() == resolvedv.Type() {
+			out.Set(resolvedv)
+			return true
+		}
+	case reflect.Ptr:
+		if out.Type().Elem() == reflect.TypeOf(resolved) {
+			// TODO DOes this make sense? When is out a Ptr except when decoding a nil value?
+			elem := reflect.New(out.Type().Elem())
+			elem.Elem().Set(reflect.ValueOf(resolved))
+			out.Set(elem)
+			return true
+		}
+	}
+	d.terror(n, tag, out)
+	return false
+}
+
+func settableValueOf(i interface{}) reflect.Value {
+	v := reflect.ValueOf(i)
+	sv := reflect.New(v.Type()).Elem()
+	sv.Set(v)
+	return sv
+}
+
+func (d *decoder) sequence(n *node, out reflect.Value) (good bool) {
+	l := len(n.children)
+
+	var iface reflect.Value
+	switch out.Kind() {
+	case reflect.Slice:
+		out.Set(reflect.MakeSlice(out.Type(), l, l))
+	case reflect.Array:
+		if l != out.Len() {
+			failf("invalid array: want %d elements but got %d", out.Len(), l)
+		}
+	case reflect.Interface:
+		// No type hints. Will have to use a generic sequence.
+		iface = out
+		out = settableValueOf(make([]interface{}, l))
+	default:
+		d.terror(n, yaml_SEQ_TAG, out)
+		return false
+	}
+	et := out.Type().Elem()
+
+	j := 0
+	for i := 0; i < l; i++ {
+		e := reflect.New(et).Elem()
+		if ok := d.unmarshal(n.children[i], e); ok {
+			out.Index(j).Set(e)
+			j++
+		}
+	}
+	if out.Kind() != reflect.Array {
+		out.Set(out.Slice(0, j))
+	}
+	if iface.IsValid() {
+		iface.Set(out)
+	}
+	return true
+}
+
+func (d *decoder) mapping(n *node, out reflect.Value) (good bool) {
+	switch out.Kind() {
+	case reflect.Struct:
+		return d.mappingStruct(n, out)
+	case reflect.Slice:
+		return d.mappingSlice(n, out)
+	case reflect.Map:
+		// okay
+	case reflect.Interface:
+		if d.mapType.Kind() == reflect.Map {
+			iface := out
+			out = reflect.MakeMap(d.mapType)
+			iface.Set(out)
+		} else {
+			slicev := reflect.New(d.mapType).Elem()
+			if !d.mappingSlice(n, slicev) {
+				return false
+			}
+			out.Set(slicev)
+			return true
+		}
+	default:
+		d.terror(n, yaml_MAP_TAG, out)
+		return false
+	}
+	outt := out.Type()
+	kt := outt.Key()
+	et := outt.Elem()
+
+	mapType := d.mapType
+	if outt.Key() == ifaceType && outt.Elem() == ifaceType {
+		d.mapType = outt
+	}
+
+	if out.IsNil() {
+		out.Set(reflect.MakeMap(outt))
+	}
+	l := len(n.children)
+	for i := 0; i < l; i += 2 {
+		if isMerge(n.children[i]) {
+			d.merge(n.children[i+1], out)
+			continue
+		}
+		k := reflect.New(kt).Elem()
+		if d.unmarshal(n.children[i], k) {
+			kkind := k.Kind()
+			if kkind == reflect.Interface {
+				kkind = k.Elem().Kind()
+			}
+			if kkind == reflect.Map || kkind == reflect.Slice {
+				failf("invalid map key: %#v", k.Interface())
+			}
+			e := reflect.New(et).Elem()
+			if d.unmarshal(n.children[i+1], e) {
+				d.setMapIndex(n.children[i+1], out, k, e)
+			}
+		}
+	}
+	d.mapType = mapType
+	return true
+}
+
+func (d *decoder) setMapIndex(n *node, out, k, v reflect.Value) {
+	if d.strict && out.MapIndex(k) != zeroValue {
+		d.terrors = append(d.terrors, fmt.Sprintf("line %d: key %#v already set in map", n.line+1, k.Interface()))
+		return
+	}
+	out.SetMapIndex(k, v)
+}
+
+func (d *decoder) mappingSlice(n *node, out reflect.Value) (good bool) {
+	outt := out.Type()
+	if outt.Elem() != mapItemType {
+		d.terror(n, yaml_MAP_TAG, out)
+		return false
+	}
+
+	mapType := d.mapType
+	d.mapType = outt
+
+	var slice []MapItem
+	var l = len(n.children)
+	for i := 0; i < l; i += 2 {
+		if isMerge(n.children[i]) {
+			d.merge(n.children[i+1], out)
+			continue
+		}
+		item := MapItem{}
+		k := reflect.ValueOf(&item.Key).Elem()
+		if d.unmarshal(n.children[i], k) {
+			v := reflect.ValueOf(&item.Value).Elem()
+			if d.unmarshal(n.children[i+1], v) {
+				slice = append(slice, item)
+			}
+		}
+	}
+	out.Set(reflect.ValueOf(slice))
+	d.mapType = mapType
+	return true
+}
+
+func (d *decoder) mappingStruct(n *node, out reflect.Value) (good bool) {
+	sinfo, err := getStructInfo(out.Type())
+	if err != nil {
+		panic(err)
+	}
+	name := settableValueOf("")
+	l := len(n.children)
+
+	var inlineMap reflect.Value
+	var elemType reflect.Type
+	if sinfo.InlineMap != -1 {
+		inlineMap = out.Field(sinfo.InlineMap)
+		inlineMap.Set(reflect.New(inlineMap.Type()).Elem())
+		elemType = inlineMap.Type().Elem()
+	}
+
+	var doneFields []bool
+	if d.strict {
+		doneFields = make([]bool, len(sinfo.FieldsList))
+	}
+	for i := 0; i < l; i += 2 {
+		ni := n.children[i]
+		if isMerge(ni) {
+			d.merge(n.children[i+1], out)
+			continue
+		}
+		if !d.unmarshal(ni, name) {
+			continue
+		}
+		if info, ok := sinfo.FieldsMap[name.String()]; ok {
+			if d.strict {
+				if doneFields[info.Id] {
+					d.terrors = append(d.terrors, fmt.Sprintf("line %d: field %s already set in type %s", ni.line+1, name.String(), out.Type()))
+					continue
+				}
+				doneFields[info.Id] = true
+			}
+			var field reflect.Value
+			if info.Inline == nil {
+				field = out.Field(info.Num)
+			} else {
+				field = out.FieldByIndex(info.Inline)
+			}
+			d.unmarshal(n.children[i+1], field)
+		} else if sinfo.InlineMap != -1 {
+			if inlineMap.IsNil() {
+				inlineMap.Set(reflect.MakeMap(inlineMap.Type()))
+			}
+			value := reflect.New(elemType).Elem()
+			d.unmarshal(n.children[i+1], value)
+			d.setMapIndex(n.children[i+1], inlineMap, name, value)
+		} else if d.strict {
+			d.terrors = append(d.terrors, fmt.Sprintf("line %d: field %s not found in type %s", ni.line+1, name.String(), out.Type()))
+		}
+	}
+	return true
+}
+
+func failWantMap() {
+	failf("map merge requires map or sequence of maps as the value")
+}
+
+func (d *decoder) merge(n *node, out reflect.Value) {
+	switch n.kind {
+	case mappingNode:
+		d.unmarshal(n, out)
+	case aliasNode:
+		an, ok := d.doc.anchors[n.value]
+		if ok && an.kind != mappingNode {
+			failWantMap()
+		}
+		d.unmarshal(n, out)
+	case sequenceNode:
+		// Step backwards as earlier nodes take precedence.
+		for i := len(n.children) - 1; i >= 0; i-- {
+			ni := n.children[i]
+			if ni.kind == aliasNode {
+				an, ok := d.doc.anchors[ni.value]
+				if ok && an.kind != mappingNode {
+					failWantMap()
+				}
+			} else if ni.kind != mappingNode {
+				failWantMap()
+			}
+			d.unmarshal(ni, out)
+		}
+	default:
+		failWantMap()
+	}
+}
+
+func isMerge(n *node) bool {
+	return n.kind == scalarNode && n.value == "<<" && (n.implicit == true || n.tag == yaml_MERGE_TAG)
+}
diff --git a/vendor/gopkg.in/yaml.v2/emitterc.go b/vendor/gopkg.in/yaml.v2/emitterc.go
new file mode 100644
index 0000000..a1c2cc5
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/emitterc.go
@@ -0,0 +1,1685 @@
+package yaml
+
+import (
+	"bytes"
+	"fmt"
+)
+
+// Flush the buffer if needed.
+func flush(emitter *yaml_emitter_t) bool {
+	if emitter.buffer_pos+5 >= len(emitter.buffer) {
+		return yaml_emitter_flush(emitter)
+	}
+	return true
+}
+
+// Put a character to the output buffer.
+func put(emitter *yaml_emitter_t, value byte) bool {
+	if emitter.buffer_pos+5 >= len(emitter.buffer) && !yaml_emitter_flush(emitter) {
+		return false
+	}
+	emitter.buffer[emitter.buffer_pos] = value
+	emitter.buffer_pos++
+	emitter.column++
+	return true
+}
+
+// Put a line break to the output buffer.
+func put_break(emitter *yaml_emitter_t) bool {
+	if emitter.buffer_pos+5 >= len(emitter.buffer) && !yaml_emitter_flush(emitter) {
+		return false
+	}
+	switch emitter.line_break {
+	case yaml_CR_BREAK:
+		emitter.buffer[emitter.buffer_pos] = '\r'
+		emitter.buffer_pos += 1
+	case yaml_LN_BREAK:
+		emitter.buffer[emitter.buffer_pos] = '\n'
+		emitter.buffer_pos += 1
+	case yaml_CRLN_BREAK:
+		emitter.buffer[emitter.buffer_pos+0] = '\r'
+		emitter.buffer[emitter.buffer_pos+1] = '\n'
+		emitter.buffer_pos += 2
+	default:
+		panic("unknown line break setting")
+	}
+	emitter.column = 0
+	emitter.line++
+	return true
+}
+
+// Copy a character from a string into buffer.
+func write(emitter *yaml_emitter_t, s []byte, i *int) bool {
+	if emitter.buffer_pos+5 >= len(emitter.buffer) && !yaml_emitter_flush(emitter) {
+		return false
+	}
+	p := emitter.buffer_pos
+	w := width(s[*i])
+	switch w {
+	case 4:
+		emitter.buffer[p+3] = s[*i+3]
+		fallthrough
+	case 3:
+		emitter.buffer[p+2] = s[*i+2]
+		fallthrough
+	case 2:
+		emitter.buffer[p+1] = s[*i+1]
+		fallthrough
+	case 1:
+		emitter.buffer[p+0] = s[*i+0]
+	default:
+		panic("unknown character width")
+	}
+	emitter.column++
+	emitter.buffer_pos += w
+	*i += w
+	return true
+}
+
+// Write a whole string into buffer.
+func write_all(emitter *yaml_emitter_t, s []byte) bool {
+	for i := 0; i < len(s); {
+		if !write(emitter, s, &i) {
+			return false
+		}
+	}
+	return true
+}
+
+// Copy a line break character from a string into buffer.
+func write_break(emitter *yaml_emitter_t, s []byte, i *int) bool {
+	if s[*i] == '\n' {
+		if !put_break(emitter) {
+			return false
+		}
+		*i++
+	} else {
+		if !write(emitter, s, i) {
+			return false
+		}
+		emitter.column = 0
+		emitter.line++
+	}
+	return true
+}
+
+// Set an emitter error and return false.
+func yaml_emitter_set_emitter_error(emitter *yaml_emitter_t, problem string) bool {
+	emitter.error = yaml_EMITTER_ERROR
+	emitter.problem = problem
+	return false
+}
+
+// Emit an event.
+func yaml_emitter_emit(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	emitter.events = append(emitter.events, *event)
+	for !yaml_emitter_need_more_events(emitter) {
+		event := &emitter.events[emitter.events_head]
+		if !yaml_emitter_analyze_event(emitter, event) {
+			return false
+		}
+		if !yaml_emitter_state_machine(emitter, event) {
+			return false
+		}
+		yaml_event_delete(event)
+		emitter.events_head++
+	}
+	return true
+}
+
+// Check if we need to accumulate more events before emitting.
+//
+// We accumulate extra
+//  - 1 event for DOCUMENT-START
+//  - 2 events for SEQUENCE-START
+//  - 3 events for MAPPING-START
+//
+func yaml_emitter_need_more_events(emitter *yaml_emitter_t) bool {
+	if emitter.events_head == len(emitter.events) {
+		return true
+	}
+	var accumulate int
+	switch emitter.events[emitter.events_head].typ {
+	case yaml_DOCUMENT_START_EVENT:
+		accumulate = 1
+		break
+	case yaml_SEQUENCE_START_EVENT:
+		accumulate = 2
+		break
+	case yaml_MAPPING_START_EVENT:
+		accumulate = 3
+		break
+	default:
+		return false
+	}
+	if len(emitter.events)-emitter.events_head > accumulate {
+		return false
+	}
+	var level int
+	for i := emitter.events_head; i < len(emitter.events); i++ {
+		switch emitter.events[i].typ {
+		case yaml_STREAM_START_EVENT, yaml_DOCUMENT_START_EVENT, yaml_SEQUENCE_START_EVENT, yaml_MAPPING_START_EVENT:
+			level++
+		case yaml_STREAM_END_EVENT, yaml_DOCUMENT_END_EVENT, yaml_SEQUENCE_END_EVENT, yaml_MAPPING_END_EVENT:
+			level--
+		}
+		if level == 0 {
+			return false
+		}
+	}
+	return true
+}
+
+// Append a directive to the directives stack.
+func yaml_emitter_append_tag_directive(emitter *yaml_emitter_t, value *yaml_tag_directive_t, allow_duplicates bool) bool {
+	for i := 0; i < len(emitter.tag_directives); i++ {
+		if bytes.Equal(value.handle, emitter.tag_directives[i].handle) {
+			if allow_duplicates {
+				return true
+			}
+			return yaml_emitter_set_emitter_error(emitter, "duplicate %TAG directive")
+		}
+	}
+
+	// [Go] Do we actually need to copy this given garbage collection
+	// and the lack of deallocating destructors?
+	tag_copy := yaml_tag_directive_t{
+		handle: make([]byte, len(value.handle)),
+		prefix: make([]byte, len(value.prefix)),
+	}
+	copy(tag_copy.handle, value.handle)
+	copy(tag_copy.prefix, value.prefix)
+	emitter.tag_directives = append(emitter.tag_directives, tag_copy)
+	return true
+}
+
+// Increase the indentation level.
+func yaml_emitter_increase_indent(emitter *yaml_emitter_t, flow, indentless bool) bool {
+	emitter.indents = append(emitter.indents, emitter.indent)
+	if emitter.indent < 0 {
+		if flow {
+			emitter.indent = emitter.best_indent
+		} else {
+			emitter.indent = 0
+		}
+	} else if !indentless {
+		emitter.indent += emitter.best_indent
+	}
+	return true
+}
+
+// State dispatcher.
+func yaml_emitter_state_machine(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	switch emitter.state {
+	default:
+	case yaml_EMIT_STREAM_START_STATE:
+		return yaml_emitter_emit_stream_start(emitter, event)
+
+	case yaml_EMIT_FIRST_DOCUMENT_START_STATE:
+		return yaml_emitter_emit_document_start(emitter, event, true)
+
+	case yaml_EMIT_DOCUMENT_START_STATE:
+		return yaml_emitter_emit_document_start(emitter, event, false)
+
+	case yaml_EMIT_DOCUMENT_CONTENT_STATE:
+		return yaml_emitter_emit_document_content(emitter, event)
+
+	case yaml_EMIT_DOCUMENT_END_STATE:
+		return yaml_emitter_emit_document_end(emitter, event)
+
+	case yaml_EMIT_FLOW_SEQUENCE_FIRST_ITEM_STATE:
+		return yaml_emitter_emit_flow_sequence_item(emitter, event, true)
+
+	case yaml_EMIT_FLOW_SEQUENCE_ITEM_STATE:
+		return yaml_emitter_emit_flow_sequence_item(emitter, event, false)
+
+	case yaml_EMIT_FLOW_MAPPING_FIRST_KEY_STATE:
+		return yaml_emitter_emit_flow_mapping_key(emitter, event, true)
+
+	case yaml_EMIT_FLOW_MAPPING_KEY_STATE:
+		return yaml_emitter_emit_flow_mapping_key(emitter, event, false)
+
+	case yaml_EMIT_FLOW_MAPPING_SIMPLE_VALUE_STATE:
+		return yaml_emitter_emit_flow_mapping_value(emitter, event, true)
+
+	case yaml_EMIT_FLOW_MAPPING_VALUE_STATE:
+		return yaml_emitter_emit_flow_mapping_value(emitter, event, false)
+
+	case yaml_EMIT_BLOCK_SEQUENCE_FIRST_ITEM_STATE:
+		return yaml_emitter_emit_block_sequence_item(emitter, event, true)
+
+	case yaml_EMIT_BLOCK_SEQUENCE_ITEM_STATE:
+		return yaml_emitter_emit_block_sequence_item(emitter, event, false)
+
+	case yaml_EMIT_BLOCK_MAPPING_FIRST_KEY_STATE:
+		return yaml_emitter_emit_block_mapping_key(emitter, event, true)
+
+	case yaml_EMIT_BLOCK_MAPPING_KEY_STATE:
+		return yaml_emitter_emit_block_mapping_key(emitter, event, false)
+
+	case yaml_EMIT_BLOCK_MAPPING_SIMPLE_VALUE_STATE:
+		return yaml_emitter_emit_block_mapping_value(emitter, event, true)
+
+	case yaml_EMIT_BLOCK_MAPPING_VALUE_STATE:
+		return yaml_emitter_emit_block_mapping_value(emitter, event, false)
+
+	case yaml_EMIT_END_STATE:
+		return yaml_emitter_set_emitter_error(emitter, "expected nothing after STREAM-END")
+	}
+	panic("invalid emitter state")
+}
+
+// Expect STREAM-START.
+func yaml_emitter_emit_stream_start(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	if event.typ != yaml_STREAM_START_EVENT {
+		return yaml_emitter_set_emitter_error(emitter, "expected STREAM-START")
+	}
+	if emitter.encoding == yaml_ANY_ENCODING {
+		emitter.encoding = event.encoding
+		if emitter.encoding == yaml_ANY_ENCODING {
+			emitter.encoding = yaml_UTF8_ENCODING
+		}
+	}
+	if emitter.best_indent < 2 || emitter.best_indent > 9 {
+		emitter.best_indent = 2
+	}
+	if emitter.best_width >= 0 && emitter.best_width <= emitter.best_indent*2 {
+		emitter.best_width = 80
+	}
+	if emitter.best_width < 0 {
+		emitter.best_width = 1<<31 - 1
+	}
+	if emitter.line_break == yaml_ANY_BREAK {
+		emitter.line_break = yaml_LN_BREAK
+	}
+
+	emitter.indent = -1
+	emitter.line = 0
+	emitter.column = 0
+	emitter.whitespace = true
+	emitter.indention = true
+
+	if emitter.encoding != yaml_UTF8_ENCODING {
+		if !yaml_emitter_write_bom(emitter) {
+			return false
+		}
+	}
+	emitter.state = yaml_EMIT_FIRST_DOCUMENT_START_STATE
+	return true
+}
+
+// Expect DOCUMENT-START or STREAM-END.
+func yaml_emitter_emit_document_start(emitter *yaml_emitter_t, event *yaml_event_t, first bool) bool {
+
+	if event.typ == yaml_DOCUMENT_START_EVENT {
+
+		if event.version_directive != nil {
+			if !yaml_emitter_analyze_version_directive(emitter, event.version_directive) {
+				return false
+			}
+		}
+
+		for i := 0; i < len(event.tag_directives); i++ {
+			tag_directive := &event.tag_directives[i]
+			if !yaml_emitter_analyze_tag_directive(emitter, tag_directive) {
+				return false
+			}
+			if !yaml_emitter_append_tag_directive(emitter, tag_directive, false) {
+				return false
+			}
+		}
+
+		for i := 0; i < len(default_tag_directives); i++ {
+			tag_directive := &default_tag_directives[i]
+			if !yaml_emitter_append_tag_directive(emitter, tag_directive, true) {
+				return false
+			}
+		}
+
+		implicit := event.implicit
+		if !first || emitter.canonical {
+			implicit = false
+		}
+
+		if emitter.open_ended && (event.version_directive != nil || len(event.tag_directives) > 0) {
+			if !yaml_emitter_write_indicator(emitter, []byte("..."), true, false, false) {
+				return false
+			}
+			if !yaml_emitter_write_indent(emitter) {
+				return false
+			}
+		}
+
+		if event.version_directive != nil {
+			implicit = false
+			if !yaml_emitter_write_indicator(emitter, []byte("%YAML"), true, false, false) {
+				return false
+			}
+			if !yaml_emitter_write_indicator(emitter, []byte("1.1"), true, false, false) {
+				return false
+			}
+			if !yaml_emitter_write_indent(emitter) {
+				return false
+			}
+		}
+
+		if len(event.tag_directives) > 0 {
+			implicit = false
+			for i := 0; i < len(event.tag_directives); i++ {
+				tag_directive := &event.tag_directives[i]
+				if !yaml_emitter_write_indicator(emitter, []byte("%TAG"), true, false, false) {
+					return false
+				}
+				if !yaml_emitter_write_tag_handle(emitter, tag_directive.handle) {
+					return false
+				}
+				if !yaml_emitter_write_tag_content(emitter, tag_directive.prefix, true) {
+					return false
+				}
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+			}
+		}
+
+		if yaml_emitter_check_empty_document(emitter) {
+			implicit = false
+		}
+		if !implicit {
+			if !yaml_emitter_write_indent(emitter) {
+				return false
+			}
+			if !yaml_emitter_write_indicator(emitter, []byte("---"), true, false, false) {
+				return false
+			}
+			if emitter.canonical {
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+			}
+		}
+
+		emitter.state = yaml_EMIT_DOCUMENT_CONTENT_STATE
+		return true
+	}
+
+	if event.typ == yaml_STREAM_END_EVENT {
+		if emitter.open_ended {
+			if !yaml_emitter_write_indicator(emitter, []byte("..."), true, false, false) {
+				return false
+			}
+			if !yaml_emitter_write_indent(emitter) {
+				return false
+			}
+		}
+		if !yaml_emitter_flush(emitter) {
+			return false
+		}
+		emitter.state = yaml_EMIT_END_STATE
+		return true
+	}
+
+	return yaml_emitter_set_emitter_error(emitter, "expected DOCUMENT-START or STREAM-END")
+}
+
+// Expect the root node.
+func yaml_emitter_emit_document_content(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	emitter.states = append(emitter.states, yaml_EMIT_DOCUMENT_END_STATE)
+	return yaml_emitter_emit_node(emitter, event, true, false, false, false)
+}
+
+// Expect DOCUMENT-END.
+func yaml_emitter_emit_document_end(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	if event.typ != yaml_DOCUMENT_END_EVENT {
+		return yaml_emitter_set_emitter_error(emitter, "expected DOCUMENT-END")
+	}
+	if !yaml_emitter_write_indent(emitter) {
+		return false
+	}
+	if !event.implicit {
+		// [Go] Allocate the slice elsewhere.
+		if !yaml_emitter_write_indicator(emitter, []byte("..."), true, false, false) {
+			return false
+		}
+		if !yaml_emitter_write_indent(emitter) {
+			return false
+		}
+	}
+	if !yaml_emitter_flush(emitter) {
+		return false
+	}
+	emitter.state = yaml_EMIT_DOCUMENT_START_STATE
+	emitter.tag_directives = emitter.tag_directives[:0]
+	return true
+}
+
+// Expect a flow item node.
+func yaml_emitter_emit_flow_sequence_item(emitter *yaml_emitter_t, event *yaml_event_t, first bool) bool {
+	if first {
+		if !yaml_emitter_write_indicator(emitter, []byte{'['}, true, true, false) {
+			return false
+		}
+		if !yaml_emitter_increase_indent(emitter, true, false) {
+			return false
+		}
+		emitter.flow_level++
+	}
+
+	if event.typ == yaml_SEQUENCE_END_EVENT {
+		emitter.flow_level--
+		emitter.indent = emitter.indents[len(emitter.indents)-1]
+		emitter.indents = emitter.indents[:len(emitter.indents)-1]
+		if emitter.canonical && !first {
+			if !yaml_emitter_write_indicator(emitter, []byte{','}, false, false, false) {
+				return false
+			}
+			if !yaml_emitter_write_indent(emitter) {
+				return false
+			}
+		}
+		if !yaml_emitter_write_indicator(emitter, []byte{']'}, false, false, false) {
+			return false
+		}
+		emitter.state = emitter.states[len(emitter.states)-1]
+		emitter.states = emitter.states[:len(emitter.states)-1]
+
+		return true
+	}
+
+	if !first {
+		if !yaml_emitter_write_indicator(emitter, []byte{','}, false, false, false) {
+			return false
+		}
+	}
+
+	if emitter.canonical || emitter.column > emitter.best_width {
+		if !yaml_emitter_write_indent(emitter) {
+			return false
+		}
+	}
+	emitter.states = append(emitter.states, yaml_EMIT_FLOW_SEQUENCE_ITEM_STATE)
+	return yaml_emitter_emit_node(emitter, event, false, true, false, false)
+}
+
+// Expect a flow key node.
+func yaml_emitter_emit_flow_mapping_key(emitter *yaml_emitter_t, event *yaml_event_t, first bool) bool {
+	if first {
+		if !yaml_emitter_write_indicator(emitter, []byte{'{'}, true, true, false) {
+			return false
+		}
+		if !yaml_emitter_increase_indent(emitter, true, false) {
+			return false
+		}
+		emitter.flow_level++
+	}
+
+	if event.typ == yaml_MAPPING_END_EVENT {
+		emitter.flow_level--
+		emitter.indent = emitter.indents[len(emitter.indents)-1]
+		emitter.indents = emitter.indents[:len(emitter.indents)-1]
+		if emitter.canonical && !first {
+			if !yaml_emitter_write_indicator(emitter, []byte{','}, false, false, false) {
+				return false
+			}
+			if !yaml_emitter_write_indent(emitter) {
+				return false
+			}
+		}
+		if !yaml_emitter_write_indicator(emitter, []byte{'}'}, false, false, false) {
+			return false
+		}
+		emitter.state = emitter.states[len(emitter.states)-1]
+		emitter.states = emitter.states[:len(emitter.states)-1]
+		return true
+	}
+
+	if !first {
+		if !yaml_emitter_write_indicator(emitter, []byte{','}, false, false, false) {
+			return false
+		}
+	}
+	if emitter.canonical || emitter.column > emitter.best_width {
+		if !yaml_emitter_write_indent(emitter) {
+			return false
+		}
+	}
+
+	if !emitter.canonical && yaml_emitter_check_simple_key(emitter) {
+		emitter.states = append(emitter.states, yaml_EMIT_FLOW_MAPPING_SIMPLE_VALUE_STATE)
+		return yaml_emitter_emit_node(emitter, event, false, false, true, true)
+	}
+	if !yaml_emitter_write_indicator(emitter, []byte{'?'}, true, false, false) {
+		return false
+	}
+	emitter.states = append(emitter.states, yaml_EMIT_FLOW_MAPPING_VALUE_STATE)
+	return yaml_emitter_emit_node(emitter, event, false, false, true, false)
+}
+
+// Expect a flow value node.
+func yaml_emitter_emit_flow_mapping_value(emitter *yaml_emitter_t, event *yaml_event_t, simple bool) bool {
+	if simple {
+		if !yaml_emitter_write_indicator(emitter, []byte{':'}, false, false, false) {
+			return false
+		}
+	} else {
+		if emitter.canonical || emitter.column > emitter.best_width {
+			if !yaml_emitter_write_indent(emitter) {
+				return false
+			}
+		}
+		if !yaml_emitter_write_indicator(emitter, []byte{':'}, true, false, false) {
+			return false
+		}
+	}
+	emitter.states = append(emitter.states, yaml_EMIT_FLOW_MAPPING_KEY_STATE)
+	return yaml_emitter_emit_node(emitter, event, false, false, true, false)
+}
+
+// Expect a block item node.
+func yaml_emitter_emit_block_sequence_item(emitter *yaml_emitter_t, event *yaml_event_t, first bool) bool {
+	if first {
+		if !yaml_emitter_increase_indent(emitter, false, emitter.mapping_context && !emitter.indention) {
+			return false
+		}
+	}
+	if event.typ == yaml_SEQUENCE_END_EVENT {
+		emitter.indent = emitter.indents[len(emitter.indents)-1]
+		emitter.indents = emitter.indents[:len(emitter.indents)-1]
+		emitter.state = emitter.states[len(emitter.states)-1]
+		emitter.states = emitter.states[:len(emitter.states)-1]
+		return true
+	}
+	if !yaml_emitter_write_indent(emitter) {
+		return false
+	}
+	if !yaml_emitter_write_indicator(emitter, []byte{'-'}, true, false, true) {
+		return false
+	}
+	emitter.states = append(emitter.states, yaml_EMIT_BLOCK_SEQUENCE_ITEM_STATE)
+	return yaml_emitter_emit_node(emitter, event, false, true, false, false)
+}
+
+// Expect a block key node.
+func yaml_emitter_emit_block_mapping_key(emitter *yaml_emitter_t, event *yaml_event_t, first bool) bool {
+	if first {
+		if !yaml_emitter_increase_indent(emitter, false, false) {
+			return false
+		}
+	}
+	if event.typ == yaml_MAPPING_END_EVENT {
+		emitter.indent = emitter.indents[len(emitter.indents)-1]
+		emitter.indents = emitter.indents[:len(emitter.indents)-1]
+		emitter.state = emitter.states[len(emitter.states)-1]
+		emitter.states = emitter.states[:len(emitter.states)-1]
+		return true
+	}
+	if !yaml_emitter_write_indent(emitter) {
+		return false
+	}
+	if yaml_emitter_check_simple_key(emitter) {
+		emitter.states = append(emitter.states, yaml_EMIT_BLOCK_MAPPING_SIMPLE_VALUE_STATE)
+		return yaml_emitter_emit_node(emitter, event, false, false, true, true)
+	}
+	if !yaml_emitter_write_indicator(emitter, []byte{'?'}, true, false, true) {
+		return false
+	}
+	emitter.states = append(emitter.states, yaml_EMIT_BLOCK_MAPPING_VALUE_STATE)
+	return yaml_emitter_emit_node(emitter, event, false, false, true, false)
+}
+
+// Expect a block value node.
+func yaml_emitter_emit_block_mapping_value(emitter *yaml_emitter_t, event *yaml_event_t, simple bool) bool {
+	if simple {
+		if !yaml_emitter_write_indicator(emitter, []byte{':'}, false, false, false) {
+			return false
+		}
+	} else {
+		if !yaml_emitter_write_indent(emitter) {
+			return false
+		}
+		if !yaml_emitter_write_indicator(emitter, []byte{':'}, true, false, true) {
+			return false
+		}
+	}
+	emitter.states = append(emitter.states, yaml_EMIT_BLOCK_MAPPING_KEY_STATE)
+	return yaml_emitter_emit_node(emitter, event, false, false, true, false)
+}
+
+// Expect a node.
+func yaml_emitter_emit_node(emitter *yaml_emitter_t, event *yaml_event_t,
+	root bool, sequence bool, mapping bool, simple_key bool) bool {
+
+	emitter.root_context = root
+	emitter.sequence_context = sequence
+	emitter.mapping_context = mapping
+	emitter.simple_key_context = simple_key
+
+	switch event.typ {
+	case yaml_ALIAS_EVENT:
+		return yaml_emitter_emit_alias(emitter, event)
+	case yaml_SCALAR_EVENT:
+		return yaml_emitter_emit_scalar(emitter, event)
+	case yaml_SEQUENCE_START_EVENT:
+		return yaml_emitter_emit_sequence_start(emitter, event)
+	case yaml_MAPPING_START_EVENT:
+		return yaml_emitter_emit_mapping_start(emitter, event)
+	default:
+		return yaml_emitter_set_emitter_error(emitter,
+			fmt.Sprintf("expected SCALAR, SEQUENCE-START, MAPPING-START, or ALIAS, but got %v", event.typ))
+	}
+}
+
+// Expect ALIAS.
+func yaml_emitter_emit_alias(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	if !yaml_emitter_process_anchor(emitter) {
+		return false
+	}
+	emitter.state = emitter.states[len(emitter.states)-1]
+	emitter.states = emitter.states[:len(emitter.states)-1]
+	return true
+}
+
+// Expect SCALAR.
+func yaml_emitter_emit_scalar(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	if !yaml_emitter_select_scalar_style(emitter, event) {
+		return false
+	}
+	if !yaml_emitter_process_anchor(emitter) {
+		return false
+	}
+	if !yaml_emitter_process_tag(emitter) {
+		return false
+	}
+	if !yaml_emitter_increase_indent(emitter, true, false) {
+		return false
+	}
+	if !yaml_emitter_process_scalar(emitter) {
+		return false
+	}
+	emitter.indent = emitter.indents[len(emitter.indents)-1]
+	emitter.indents = emitter.indents[:len(emitter.indents)-1]
+	emitter.state = emitter.states[len(emitter.states)-1]
+	emitter.states = emitter.states[:len(emitter.states)-1]
+	return true
+}
+
+// Expect SEQUENCE-START.
+func yaml_emitter_emit_sequence_start(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	if !yaml_emitter_process_anchor(emitter) {
+		return false
+	}
+	if !yaml_emitter_process_tag(emitter) {
+		return false
+	}
+	if emitter.flow_level > 0 || emitter.canonical || event.sequence_style() == yaml_FLOW_SEQUENCE_STYLE ||
+		yaml_emitter_check_empty_sequence(emitter) {
+		emitter.state = yaml_EMIT_FLOW_SEQUENCE_FIRST_ITEM_STATE
+	} else {
+		emitter.state = yaml_EMIT_BLOCK_SEQUENCE_FIRST_ITEM_STATE
+	}
+	return true
+}
+
+// Expect MAPPING-START.
+func yaml_emitter_emit_mapping_start(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	if !yaml_emitter_process_anchor(emitter) {
+		return false
+	}
+	if !yaml_emitter_process_tag(emitter) {
+		return false
+	}
+	if emitter.flow_level > 0 || emitter.canonical || event.mapping_style() == yaml_FLOW_MAPPING_STYLE ||
+		yaml_emitter_check_empty_mapping(emitter) {
+		emitter.state = yaml_EMIT_FLOW_MAPPING_FIRST_KEY_STATE
+	} else {
+		emitter.state = yaml_EMIT_BLOCK_MAPPING_FIRST_KEY_STATE
+	}
+	return true
+}
+
+// Check if the document content is an empty scalar.
+func yaml_emitter_check_empty_document(emitter *yaml_emitter_t) bool {
+	return false // [Go] Huh?
+}
+
+// Check if the next events represent an empty sequence.
+func yaml_emitter_check_empty_sequence(emitter *yaml_emitter_t) bool {
+	if len(emitter.events)-emitter.events_head < 2 {
+		return false
+	}
+	return emitter.events[emitter.events_head].typ == yaml_SEQUENCE_START_EVENT &&
+		emitter.events[emitter.events_head+1].typ == yaml_SEQUENCE_END_EVENT
+}
+
+// Check if the next events represent an empty mapping.
+func yaml_emitter_check_empty_mapping(emitter *yaml_emitter_t) bool {
+	if len(emitter.events)-emitter.events_head < 2 {
+		return false
+	}
+	return emitter.events[emitter.events_head].typ == yaml_MAPPING_START_EVENT &&
+		emitter.events[emitter.events_head+1].typ == yaml_MAPPING_END_EVENT
+}
+
+// Check if the next node can be expressed as a simple key.
+func yaml_emitter_check_simple_key(emitter *yaml_emitter_t) bool {
+	length := 0
+	switch emitter.events[emitter.events_head].typ {
+	case yaml_ALIAS_EVENT:
+		length += len(emitter.anchor_data.anchor)
+	case yaml_SCALAR_EVENT:
+		if emitter.scalar_data.multiline {
+			return false
+		}
+		length += len(emitter.anchor_data.anchor) +
+			len(emitter.tag_data.handle) +
+			len(emitter.tag_data.suffix) +
+			len(emitter.scalar_data.value)
+	case yaml_SEQUENCE_START_EVENT:
+		if !yaml_emitter_check_empty_sequence(emitter) {
+			return false
+		}
+		length += len(emitter.anchor_data.anchor) +
+			len(emitter.tag_data.handle) +
+			len(emitter.tag_data.suffix)
+	case yaml_MAPPING_START_EVENT:
+		if !yaml_emitter_check_empty_mapping(emitter) {
+			return false
+		}
+		length += len(emitter.anchor_data.anchor) +
+			len(emitter.tag_data.handle) +
+			len(emitter.tag_data.suffix)
+	default:
+		return false
+	}
+	return length <= 128
+}
+
+// Determine an acceptable scalar style.
+func yaml_emitter_select_scalar_style(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+
+	no_tag := len(emitter.tag_data.handle) == 0 && len(emitter.tag_data.suffix) == 0
+	if no_tag && !event.implicit && !event.quoted_implicit {
+		return yaml_emitter_set_emitter_error(emitter, "neither tag nor implicit flags are specified")
+	}
+
+	style := event.scalar_style()
+	if style == yaml_ANY_SCALAR_STYLE {
+		style = yaml_PLAIN_SCALAR_STYLE
+	}
+	if emitter.canonical {
+		style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+	}
+	if emitter.simple_key_context && emitter.scalar_data.multiline {
+		style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+	}
+
+	if style == yaml_PLAIN_SCALAR_STYLE {
+		if emitter.flow_level > 0 && !emitter.scalar_data.flow_plain_allowed ||
+			emitter.flow_level == 0 && !emitter.scalar_data.block_plain_allowed {
+			style = yaml_SINGLE_QUOTED_SCALAR_STYLE
+		}
+		if len(emitter.scalar_data.value) == 0 && (emitter.flow_level > 0 || emitter.simple_key_context) {
+			style = yaml_SINGLE_QUOTED_SCALAR_STYLE
+		}
+		if no_tag && !event.implicit {
+			style = yaml_SINGLE_QUOTED_SCALAR_STYLE
+		}
+	}
+	if style == yaml_SINGLE_QUOTED_SCALAR_STYLE {
+		if !emitter.scalar_data.single_quoted_allowed {
+			style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+		}
+	}
+	if style == yaml_LITERAL_SCALAR_STYLE || style == yaml_FOLDED_SCALAR_STYLE {
+		if !emitter.scalar_data.block_allowed || emitter.flow_level > 0 || emitter.simple_key_context {
+			style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+		}
+	}
+
+	if no_tag && !event.quoted_implicit && style != yaml_PLAIN_SCALAR_STYLE {
+		emitter.tag_data.handle = []byte{'!'}
+	}
+	emitter.scalar_data.style = style
+	return true
+}
+
+// Write an anchor.
+func yaml_emitter_process_anchor(emitter *yaml_emitter_t) bool {
+	if emitter.anchor_data.anchor == nil {
+		return true
+	}
+	c := []byte{'&'}
+	if emitter.anchor_data.alias {
+		c[0] = '*'
+	}
+	if !yaml_emitter_write_indicator(emitter, c, true, false, false) {
+		return false
+	}
+	return yaml_emitter_write_anchor(emitter, emitter.anchor_data.anchor)
+}
+
+// Write a tag.
+func yaml_emitter_process_tag(emitter *yaml_emitter_t) bool {
+	if len(emitter.tag_data.handle) == 0 && len(emitter.tag_data.suffix) == 0 {
+		return true
+	}
+	if len(emitter.tag_data.handle) > 0 {
+		if !yaml_emitter_write_tag_handle(emitter, emitter.tag_data.handle) {
+			return false
+		}
+		if len(emitter.tag_data.suffix) > 0 {
+			if !yaml_emitter_write_tag_content(emitter, emitter.tag_data.suffix, false) {
+				return false
+			}
+		}
+	} else {
+		// [Go] Allocate these slices elsewhere.
+		if !yaml_emitter_write_indicator(emitter, []byte("!<"), true, false, false) {
+			return false
+		}
+		if !yaml_emitter_write_tag_content(emitter, emitter.tag_data.suffix, false) {
+			return false
+		}
+		if !yaml_emitter_write_indicator(emitter, []byte{'>'}, false, false, false) {
+			return false
+		}
+	}
+	return true
+}
+
+// Write a scalar.
+func yaml_emitter_process_scalar(emitter *yaml_emitter_t) bool {
+	switch emitter.scalar_data.style {
+	case yaml_PLAIN_SCALAR_STYLE:
+		return yaml_emitter_write_plain_scalar(emitter, emitter.scalar_data.value, !emitter.simple_key_context)
+
+	case yaml_SINGLE_QUOTED_SCALAR_STYLE:
+		return yaml_emitter_write_single_quoted_scalar(emitter, emitter.scalar_data.value, !emitter.simple_key_context)
+
+	case yaml_DOUBLE_QUOTED_SCALAR_STYLE:
+		return yaml_emitter_write_double_quoted_scalar(emitter, emitter.scalar_data.value, !emitter.simple_key_context)
+
+	case yaml_LITERAL_SCALAR_STYLE:
+		return yaml_emitter_write_literal_scalar(emitter, emitter.scalar_data.value)
+
+	case yaml_FOLDED_SCALAR_STYLE:
+		return yaml_emitter_write_folded_scalar(emitter, emitter.scalar_data.value)
+	}
+	panic("unknown scalar style")
+}
+
+// Check if a %YAML directive is valid.
+func yaml_emitter_analyze_version_directive(emitter *yaml_emitter_t, version_directive *yaml_version_directive_t) bool {
+	if version_directive.major != 1 || version_directive.minor != 1 {
+		return yaml_emitter_set_emitter_error(emitter, "incompatible %YAML directive")
+	}
+	return true
+}
+
+// Check if a %TAG directive is valid.
+func yaml_emitter_analyze_tag_directive(emitter *yaml_emitter_t, tag_directive *yaml_tag_directive_t) bool {
+	handle := tag_directive.handle
+	prefix := tag_directive.prefix
+	if len(handle) == 0 {
+		return yaml_emitter_set_emitter_error(emitter, "tag handle must not be empty")
+	}
+	if handle[0] != '!' {
+		return yaml_emitter_set_emitter_error(emitter, "tag handle must start with '!'")
+	}
+	if handle[len(handle)-1] != '!' {
+		return yaml_emitter_set_emitter_error(emitter, "tag handle must end with '!'")
+	}
+	for i := 1; i < len(handle)-1; i += width(handle[i]) {
+		if !is_alpha(handle, i) {
+			return yaml_emitter_set_emitter_error(emitter, "tag handle must contain alphanumerical characters only")
+		}
+	}
+	if len(prefix) == 0 {
+		return yaml_emitter_set_emitter_error(emitter, "tag prefix must not be empty")
+	}
+	return true
+}
+
+// Check if an anchor is valid.
+func yaml_emitter_analyze_anchor(emitter *yaml_emitter_t, anchor []byte, alias bool) bool {
+	if len(anchor) == 0 {
+		problem := "anchor value must not be empty"
+		if alias {
+			problem = "alias value must not be empty"
+		}
+		return yaml_emitter_set_emitter_error(emitter, problem)
+	}
+	for i := 0; i < len(anchor); i += width(anchor[i]) {
+		if !is_alpha(anchor, i) {
+			problem := "anchor value must contain alphanumerical characters only"
+			if alias {
+				problem = "alias value must contain alphanumerical characters only"
+			}
+			return yaml_emitter_set_emitter_error(emitter, problem)
+		}
+	}
+	emitter.anchor_data.anchor = anchor
+	emitter.anchor_data.alias = alias
+	return true
+}
+
+// Check if a tag is valid.
+func yaml_emitter_analyze_tag(emitter *yaml_emitter_t, tag []byte) bool {
+	if len(tag) == 0 {
+		return yaml_emitter_set_emitter_error(emitter, "tag value must not be empty")
+	}
+	for i := 0; i < len(emitter.tag_directives); i++ {
+		tag_directive := &emitter.tag_directives[i]
+		if bytes.HasPrefix(tag, tag_directive.prefix) {
+			emitter.tag_data.handle = tag_directive.handle
+			emitter.tag_data.suffix = tag[len(tag_directive.prefix):]
+			return true
+		}
+	}
+	emitter.tag_data.suffix = tag
+	return true
+}
+
+// Check if a scalar is valid.
+func yaml_emitter_analyze_scalar(emitter *yaml_emitter_t, value []byte) bool {
+	var (
+		block_indicators   = false
+		flow_indicators    = false
+		line_breaks        = false
+		special_characters = false
+
+		leading_space  = false
+		leading_break  = false
+		trailing_space = false
+		trailing_break = false
+		break_space    = false
+		space_break    = false
+
+		preceded_by_whitespace = false
+		followed_by_whitespace = false
+		previous_space         = false
+		previous_break         = false
+	)
+
+	emitter.scalar_data.value = value
+
+	if len(value) == 0 {
+		emitter.scalar_data.multiline = false
+		emitter.scalar_data.flow_plain_allowed = false
+		emitter.scalar_data.block_plain_allowed = true
+		emitter.scalar_data.single_quoted_allowed = true
+		emitter.scalar_data.block_allowed = false
+		return true
+	}
+
+	if len(value) >= 3 && ((value[0] == '-' && value[1] == '-' && value[2] == '-') || (value[0] == '.' && value[1] == '.' && value[2] == '.')) {
+		block_indicators = true
+		flow_indicators = true
+	}
+
+	preceded_by_whitespace = true
+	for i, w := 0, 0; i < len(value); i += w {
+		w = width(value[i])
+		followed_by_whitespace = i+w >= len(value) || is_blank(value, i+w)
+
+		if i == 0 {
+			switch value[i] {
+			case '#', ',', '[', ']', '{', '}', '&', '*', '!', '|', '>', '\'', '"', '%', '@', '`':
+				flow_indicators = true
+				block_indicators = true
+			case '?', ':':
+				flow_indicators = true
+				if followed_by_whitespace {
+					block_indicators = true
+				}
+			case '-':
+				if followed_by_whitespace {
+					flow_indicators = true
+					block_indicators = true
+				}
+			}
+		} else {
+			switch value[i] {
+			case ',', '?', '[', ']', '{', '}':
+				flow_indicators = true
+			case ':':
+				flow_indicators = true
+				if followed_by_whitespace {
+					block_indicators = true
+				}
+			case '#':
+				if preceded_by_whitespace {
+					flow_indicators = true
+					block_indicators = true
+				}
+			}
+		}
+
+		if !is_printable(value, i) || !is_ascii(value, i) && !emitter.unicode {
+			special_characters = true
+		}
+		if is_space(value, i) {
+			if i == 0 {
+				leading_space = true
+			}
+			if i+width(value[i]) == len(value) {
+				trailing_space = true
+			}
+			if previous_break {
+				break_space = true
+			}
+			previous_space = true
+			previous_break = false
+		} else if is_break(value, i) {
+			line_breaks = true
+			if i == 0 {
+				leading_break = true
+			}
+			if i+width(value[i]) == len(value) {
+				trailing_break = true
+			}
+			if previous_space {
+				space_break = true
+			}
+			previous_space = false
+			previous_break = true
+		} else {
+			previous_space = false
+			previous_break = false
+		}
+
+		// [Go]: Why 'z'? Couldn't be the end of the string as that's the loop condition.
+		preceded_by_whitespace = is_blankz(value, i)
+	}
+
+	emitter.scalar_data.multiline = line_breaks
+	emitter.scalar_data.flow_plain_allowed = true
+	emitter.scalar_data.block_plain_allowed = true
+	emitter.scalar_data.single_quoted_allowed = true
+	emitter.scalar_data.block_allowed = true
+
+	if leading_space || leading_break || trailing_space || trailing_break {
+		emitter.scalar_data.flow_plain_allowed = false
+		emitter.scalar_data.block_plain_allowed = false
+	}
+	if trailing_space {
+		emitter.scalar_data.block_allowed = false
+	}
+	if break_space {
+		emitter.scalar_data.flow_plain_allowed = false
+		emitter.scalar_data.block_plain_allowed = false
+		emitter.scalar_data.single_quoted_allowed = false
+	}
+	if space_break || special_characters {
+		emitter.scalar_data.flow_plain_allowed = false
+		emitter.scalar_data.block_plain_allowed = false
+		emitter.scalar_data.single_quoted_allowed = false
+		emitter.scalar_data.block_allowed = false
+	}
+	if line_breaks {
+		emitter.scalar_data.flow_plain_allowed = false
+		emitter.scalar_data.block_plain_allowed = false
+	}
+	if flow_indicators {
+		emitter.scalar_data.flow_plain_allowed = false
+	}
+	if block_indicators {
+		emitter.scalar_data.block_plain_allowed = false
+	}
+	return true
+}
+
+// Check if the event data is valid.
+func yaml_emitter_analyze_event(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+
+	emitter.anchor_data.anchor = nil
+	emitter.tag_data.handle = nil
+	emitter.tag_data.suffix = nil
+	emitter.scalar_data.value = nil
+
+	switch event.typ {
+	case yaml_ALIAS_EVENT:
+		if !yaml_emitter_analyze_anchor(emitter, event.anchor, true) {
+			return false
+		}
+
+	case yaml_SCALAR_EVENT:
+		if len(event.anchor) > 0 {
+			if !yaml_emitter_analyze_anchor(emitter, event.anchor, false) {
+				return false
+			}
+		}
+		if len(event.tag) > 0 && (emitter.canonical || (!event.implicit && !event.quoted_implicit)) {
+			if !yaml_emitter_analyze_tag(emitter, event.tag) {
+				return false
+			}
+		}
+		if !yaml_emitter_analyze_scalar(emitter, event.value) {
+			return false
+		}
+
+	case yaml_SEQUENCE_START_EVENT:
+		if len(event.anchor) > 0 {
+			if !yaml_emitter_analyze_anchor(emitter, event.anchor, false) {
+				return false
+			}
+		}
+		if len(event.tag) > 0 && (emitter.canonical || !event.implicit) {
+			if !yaml_emitter_analyze_tag(emitter, event.tag) {
+				return false
+			}
+		}
+
+	case yaml_MAPPING_START_EVENT:
+		if len(event.anchor) > 0 {
+			if !yaml_emitter_analyze_anchor(emitter, event.anchor, false) {
+				return false
+			}
+		}
+		if len(event.tag) > 0 && (emitter.canonical || !event.implicit) {
+			if !yaml_emitter_analyze_tag(emitter, event.tag) {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// Write the BOM character.
+func yaml_emitter_write_bom(emitter *yaml_emitter_t) bool {
+	if !flush(emitter) {
+		return false
+	}
+	pos := emitter.buffer_pos
+	emitter.buffer[pos+0] = '\xEF'
+	emitter.buffer[pos+1] = '\xBB'
+	emitter.buffer[pos+2] = '\xBF'
+	emitter.buffer_pos += 3
+	return true
+}
+
+func yaml_emitter_write_indent(emitter *yaml_emitter_t) bool {
+	indent := emitter.indent
+	if indent < 0 {
+		indent = 0
+	}
+	if !emitter.indention || emitter.column > indent || (emitter.column == indent && !emitter.whitespace) {
+		if !put_break(emitter) {
+			return false
+		}
+	}
+	for emitter.column < indent {
+		if !put(emitter, ' ') {
+			return false
+		}
+	}
+	emitter.whitespace = true
+	emitter.indention = true
+	return true
+}
+
+func yaml_emitter_write_indicator(emitter *yaml_emitter_t, indicator []byte, need_whitespace, is_whitespace, is_indention bool) bool {
+	if need_whitespace && !emitter.whitespace {
+		if !put(emitter, ' ') {
+			return false
+		}
+	}
+	if !write_all(emitter, indicator) {
+		return false
+	}
+	emitter.whitespace = is_whitespace
+	emitter.indention = (emitter.indention && is_indention)
+	emitter.open_ended = false
+	return true
+}
+
+func yaml_emitter_write_anchor(emitter *yaml_emitter_t, value []byte) bool {
+	if !write_all(emitter, value) {
+		return false
+	}
+	emitter.whitespace = false
+	emitter.indention = false
+	return true
+}
+
+func yaml_emitter_write_tag_handle(emitter *yaml_emitter_t, value []byte) bool {
+	if !emitter.whitespace {
+		if !put(emitter, ' ') {
+			return false
+		}
+	}
+	if !write_all(emitter, value) {
+		return false
+	}
+	emitter.whitespace = false
+	emitter.indention = false
+	return true
+}
+
+func yaml_emitter_write_tag_content(emitter *yaml_emitter_t, value []byte, need_whitespace bool) bool {
+	if need_whitespace && !emitter.whitespace {
+		if !put(emitter, ' ') {
+			return false
+		}
+	}
+	for i := 0; i < len(value); {
+		var must_write bool
+		switch value[i] {
+		case ';', '/', '?', ':', '@', '&', '=', '+', '$', ',', '_', '.', '~', '*', '\'', '(', ')', '[', ']':
+			must_write = true
+		default:
+			must_write = is_alpha(value, i)
+		}
+		if must_write {
+			if !write(emitter, value, &i) {
+				return false
+			}
+		} else {
+			w := width(value[i])
+			for k := 0; k < w; k++ {
+				octet := value[i]
+				i++
+				if !put(emitter, '%') {
+					return false
+				}
+
+				c := octet >> 4
+				if c < 10 {
+					c += '0'
+				} else {
+					c += 'A' - 10
+				}
+				if !put(emitter, c) {
+					return false
+				}
+
+				c = octet & 0x0f
+				if c < 10 {
+					c += '0'
+				} else {
+					c += 'A' - 10
+				}
+				if !put(emitter, c) {
+					return false
+				}
+			}
+		}
+	}
+	emitter.whitespace = false
+	emitter.indention = false
+	return true
+}
+
+func yaml_emitter_write_plain_scalar(emitter *yaml_emitter_t, value []byte, allow_breaks bool) bool {
+	if !emitter.whitespace {
+		if !put(emitter, ' ') {
+			return false
+		}
+	}
+
+	spaces := false
+	breaks := false
+	for i := 0; i < len(value); {
+		if is_space(value, i) {
+			if allow_breaks && !spaces && emitter.column > emitter.best_width && !is_space(value, i+1) {
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+				i += width(value[i])
+			} else {
+				if !write(emitter, value, &i) {
+					return false
+				}
+			}
+			spaces = true
+		} else if is_break(value, i) {
+			if !breaks && value[i] == '\n' {
+				if !put_break(emitter) {
+					return false
+				}
+			}
+			if !write_break(emitter, value, &i) {
+				return false
+			}
+			emitter.indention = true
+			breaks = true
+		} else {
+			if breaks {
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+			}
+			if !write(emitter, value, &i) {
+				return false
+			}
+			emitter.indention = false
+			spaces = false
+			breaks = false
+		}
+	}
+
+	emitter.whitespace = false
+	emitter.indention = false
+	if emitter.root_context {
+		emitter.open_ended = true
+	}
+
+	return true
+}
+
+func yaml_emitter_write_single_quoted_scalar(emitter *yaml_emitter_t, value []byte, allow_breaks bool) bool {
+
+	if !yaml_emitter_write_indicator(emitter, []byte{'\''}, true, false, false) {
+		return false
+	}
+
+	spaces := false
+	breaks := false
+	for i := 0; i < len(value); {
+		if is_space(value, i) {
+			if allow_breaks && !spaces && emitter.column > emitter.best_width && i > 0 && i < len(value)-1 && !is_space(value, i+1) {
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+				i += width(value[i])
+			} else {
+				if !write(emitter, value, &i) {
+					return false
+				}
+			}
+			spaces = true
+		} else if is_break(value, i) {
+			if !breaks && value[i] == '\n' {
+				if !put_break(emitter) {
+					return false
+				}
+			}
+			if !write_break(emitter, value, &i) {
+				return false
+			}
+			emitter.indention = true
+			breaks = true
+		} else {
+			if breaks {
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+			}
+			if value[i] == '\'' {
+				if !put(emitter, '\'') {
+					return false
+				}
+			}
+			if !write(emitter, value, &i) {
+				return false
+			}
+			emitter.indention = false
+			spaces = false
+			breaks = false
+		}
+	}
+	if !yaml_emitter_write_indicator(emitter, []byte{'\''}, false, false, false) {
+		return false
+	}
+	emitter.whitespace = false
+	emitter.indention = false
+	return true
+}
+
+func yaml_emitter_write_double_quoted_scalar(emitter *yaml_emitter_t, value []byte, allow_breaks bool) bool {
+	spaces := false
+	if !yaml_emitter_write_indicator(emitter, []byte{'"'}, true, false, false) {
+		return false
+	}
+
+	for i := 0; i < len(value); {
+		if !is_printable(value, i) || (!emitter.unicode && !is_ascii(value, i)) ||
+			is_bom(value, i) || is_break(value, i) ||
+			value[i] == '"' || value[i] == '\\' {
+
+			octet := value[i]
+
+			var w int
+			var v rune
+			switch {
+			case octet&0x80 == 0x00:
+				w, v = 1, rune(octet&0x7F)
+			case octet&0xE0 == 0xC0:
+				w, v = 2, rune(octet&0x1F)
+			case octet&0xF0 == 0xE0:
+				w, v = 3, rune(octet&0x0F)
+			case octet&0xF8 == 0xF0:
+				w, v = 4, rune(octet&0x07)
+			}
+			for k := 1; k < w; k++ {
+				octet = value[i+k]
+				v = (v << 6) + (rune(octet) & 0x3F)
+			}
+			i += w
+
+			if !put(emitter, '\\') {
+				return false
+			}
+
+			var ok bool
+			switch v {
+			case 0x00:
+				ok = put(emitter, '0')
+			case 0x07:
+				ok = put(emitter, 'a')
+			case 0x08:
+				ok = put(emitter, 'b')
+			case 0x09:
+				ok = put(emitter, 't')
+			case 0x0A:
+				ok = put(emitter, 'n')
+			case 0x0b:
+				ok = put(emitter, 'v')
+			case 0x0c:
+				ok = put(emitter, 'f')
+			case 0x0d:
+				ok = put(emitter, 'r')
+			case 0x1b:
+				ok = put(emitter, 'e')
+			case 0x22:
+				ok = put(emitter, '"')
+			case 0x5c:
+				ok = put(emitter, '\\')
+			case 0x85:
+				ok = put(emitter, 'N')
+			case 0xA0:
+				ok = put(emitter, '_')
+			case 0x2028:
+				ok = put(emitter, 'L')
+			case 0x2029:
+				ok = put(emitter, 'P')
+			default:
+				if v <= 0xFF {
+					ok = put(emitter, 'x')
+					w = 2
+				} else if v <= 0xFFFF {
+					ok = put(emitter, 'u')
+					w = 4
+				} else {
+					ok = put(emitter, 'U')
+					w = 8
+				}
+				for k := (w - 1) * 4; ok && k >= 0; k -= 4 {
+					digit := byte((v >> uint(k)) & 0x0F)
+					if digit < 10 {
+						ok = put(emitter, digit+'0')
+					} else {
+						ok = put(emitter, digit+'A'-10)
+					}
+				}
+			}
+			if !ok {
+				return false
+			}
+			spaces = false
+		} else if is_space(value, i) {
+			if allow_breaks && !spaces && emitter.column > emitter.best_width && i > 0 && i < len(value)-1 {
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+				if is_space(value, i+1) {
+					if !put(emitter, '\\') {
+						return false
+					}
+				}
+				i += width(value[i])
+			} else if !write(emitter, value, &i) {
+				return false
+			}
+			spaces = true
+		} else {
+			if !write(emitter, value, &i) {
+				return false
+			}
+			spaces = false
+		}
+	}
+	if !yaml_emitter_write_indicator(emitter, []byte{'"'}, false, false, false) {
+		return false
+	}
+	emitter.whitespace = false
+	emitter.indention = false
+	return true
+}
+
+func yaml_emitter_write_block_scalar_hints(emitter *yaml_emitter_t, value []byte) bool {
+	if is_space(value, 0) || is_break(value, 0) {
+		indent_hint := []byte{'0' + byte(emitter.best_indent)}
+		if !yaml_emitter_write_indicator(emitter, indent_hint, false, false, false) {
+			return false
+		}
+	}
+
+	emitter.open_ended = false
+
+	var chomp_hint [1]byte
+	if len(value) == 0 {
+		chomp_hint[0] = '-'
+	} else {
+		i := len(value) - 1
+		for value[i]&0xC0 == 0x80 {
+			i--
+		}
+		if !is_break(value, i) {
+			chomp_hint[0] = '-'
+		} else if i == 0 {
+			chomp_hint[0] = '+'
+			emitter.open_ended = true
+		} else {
+			i--
+			for value[i]&0xC0 == 0x80 {
+				i--
+			}
+			if is_break(value, i) {
+				chomp_hint[0] = '+'
+				emitter.open_ended = true
+			}
+		}
+	}
+	if chomp_hint[0] != 0 {
+		if !yaml_emitter_write_indicator(emitter, chomp_hint[:], false, false, false) {
+			return false
+		}
+	}
+	return true
+}
+
+func yaml_emitter_write_literal_scalar(emitter *yaml_emitter_t, value []byte) bool {
+	if !yaml_emitter_write_indicator(emitter, []byte{'|'}, true, false, false) {
+		return false
+	}
+	if !yaml_emitter_write_block_scalar_hints(emitter, value) {
+		return false
+	}
+	if !put_break(emitter) {
+		return false
+	}
+	emitter.indention = true
+	emitter.whitespace = true
+	breaks := true
+	for i := 0; i < len(value); {
+		if is_break(value, i) {
+			if !write_break(emitter, value, &i) {
+				return false
+			}
+			emitter.indention = true
+			breaks = true
+		} else {
+			if breaks {
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+			}
+			if !write(emitter, value, &i) {
+				return false
+			}
+			emitter.indention = false
+			breaks = false
+		}
+	}
+
+	return true
+}
+
+func yaml_emitter_write_folded_scalar(emitter *yaml_emitter_t, value []byte) bool {
+	if !yaml_emitter_write_indicator(emitter, []byte{'>'}, true, false, false) {
+		return false
+	}
+	if !yaml_emitter_write_block_scalar_hints(emitter, value) {
+		return false
+	}
+
+	if !put_break(emitter) {
+		return false
+	}
+	emitter.indention = true
+	emitter.whitespace = true
+
+	breaks := true
+	leading_spaces := true
+	for i := 0; i < len(value); {
+		if is_break(value, i) {
+			if !breaks && !leading_spaces && value[i] == '\n' {
+				k := 0
+				for is_break(value, k) {
+					k += width(value[k])
+				}
+				if !is_blankz(value, k) {
+					if !put_break(emitter) {
+						return false
+					}
+				}
+			}
+			if !write_break(emitter, value, &i) {
+				return false
+			}
+			emitter.indention = true
+			breaks = true
+		} else {
+			if breaks {
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+				leading_spaces = is_blank(value, i)
+			}
+			if !breaks && is_space(value, i) && !is_space(value, i+1) && emitter.column > emitter.best_width {
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+				i += width(value[i])
+			} else {
+				if !write(emitter, value, &i) {
+					return false
+				}
+			}
+			emitter.indention = false
+			breaks = false
+		}
+	}
+	return true
+}
diff --git a/vendor/gopkg.in/yaml.v2/encode.go b/vendor/gopkg.in/yaml.v2/encode.go
new file mode 100644
index 0000000..a14435e
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/encode.go
@@ -0,0 +1,362 @@
+package yaml
+
+import (
+	"encoding"
+	"fmt"
+	"io"
+	"reflect"
+	"regexp"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+	"unicode/utf8"
+)
+
+type encoder struct {
+	emitter yaml_emitter_t
+	event   yaml_event_t
+	out     []byte
+	flow    bool
+	// doneInit holds whether the initial stream_start_event has been
+	// emitted.
+	doneInit bool
+}
+
+func newEncoder() *encoder {
+	e := &encoder{}
+	yaml_emitter_initialize(&e.emitter)
+	yaml_emitter_set_output_string(&e.emitter, &e.out)
+	yaml_emitter_set_unicode(&e.emitter, true)
+	return e
+}
+
+func newEncoderWithWriter(w io.Writer) *encoder {
+	e := &encoder{}
+	yaml_emitter_initialize(&e.emitter)
+	yaml_emitter_set_output_writer(&e.emitter, w)
+	yaml_emitter_set_unicode(&e.emitter, true)
+	return e
+}
+
+func (e *encoder) init() {
+	if e.doneInit {
+		return
+	}
+	yaml_stream_start_event_initialize(&e.event, yaml_UTF8_ENCODING)
+	e.emit()
+	e.doneInit = true
+}
+
+func (e *encoder) finish() {
+	e.emitter.open_ended = false
+	yaml_stream_end_event_initialize(&e.event)
+	e.emit()
+}
+
+func (e *encoder) destroy() {
+	yaml_emitter_delete(&e.emitter)
+}
+
+func (e *encoder) emit() {
+	// This will internally delete the e.event value.
+	e.must(yaml_emitter_emit(&e.emitter, &e.event))
+}
+
+func (e *encoder) must(ok bool) {
+	if !ok {
+		msg := e.emitter.problem
+		if msg == "" {
+			msg = "unknown problem generating YAML content"
+		}
+		failf("%s", msg)
+	}
+}
+
+func (e *encoder) marshalDoc(tag string, in reflect.Value) {
+	e.init()
+	yaml_document_start_event_initialize(&e.event, nil, nil, true)
+	e.emit()
+	e.marshal(tag, in)
+	yaml_document_end_event_initialize(&e.event, true)
+	e.emit()
+}
+
+func (e *encoder) marshal(tag string, in reflect.Value) {
+	if !in.IsValid() || in.Kind() == reflect.Ptr && in.IsNil() {
+		e.nilv()
+		return
+	}
+	iface := in.Interface()
+	switch m := iface.(type) {
+	case time.Time, *time.Time:
+		// Although time.Time implements TextMarshaler,
+		// we don't want to treat it as a string for YAML
+		// purposes because YAML has special support for
+		// timestamps.
+	case Marshaler:
+		v, err := m.MarshalYAML()
+		if err != nil {
+			fail(err)
+		}
+		if v == nil {
+			e.nilv()
+			return
+		}
+		in = reflect.ValueOf(v)
+	case encoding.TextMarshaler:
+		text, err := m.MarshalText()
+		if err != nil {
+			fail(err)
+		}
+		in = reflect.ValueOf(string(text))
+	case nil:
+		e.nilv()
+		return
+	}
+	switch in.Kind() {
+	case reflect.Interface:
+		e.marshal(tag, in.Elem())
+	case reflect.Map:
+		e.mapv(tag, in)
+	case reflect.Ptr:
+		if in.Type() == ptrTimeType {
+			e.timev(tag, in.Elem())
+		} else {
+			e.marshal(tag, in.Elem())
+		}
+	case reflect.Struct:
+		if in.Type() == timeType {
+			e.timev(tag, in)
+		} else {
+			e.structv(tag, in)
+		}
+	case reflect.Slice, reflect.Array:
+		if in.Type().Elem() == mapItemType {
+			e.itemsv(tag, in)
+		} else {
+			e.slicev(tag, in)
+		}
+	case reflect.String:
+		e.stringv(tag, in)
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		if in.Type() == durationType {
+			e.stringv(tag, reflect.ValueOf(iface.(time.Duration).String()))
+		} else {
+			e.intv(tag, in)
+		}
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		e.uintv(tag, in)
+	case reflect.Float32, reflect.Float64:
+		e.floatv(tag, in)
+	case reflect.Bool:
+		e.boolv(tag, in)
+	default:
+		panic("cannot marshal type: " + in.Type().String())
+	}
+}
+
+func (e *encoder) mapv(tag string, in reflect.Value) {
+	e.mappingv(tag, func() {
+		keys := keyList(in.MapKeys())
+		sort.Sort(keys)
+		for _, k := range keys {
+			e.marshal("", k)
+			e.marshal("", in.MapIndex(k))
+		}
+	})
+}
+
+func (e *encoder) itemsv(tag string, in reflect.Value) {
+	e.mappingv(tag, func() {
+		slice := in.Convert(reflect.TypeOf([]MapItem{})).Interface().([]MapItem)
+		for _, item := range slice {
+			e.marshal("", reflect.ValueOf(item.Key))
+			e.marshal("", reflect.ValueOf(item.Value))
+		}
+	})
+}
+
+func (e *encoder) structv(tag string, in reflect.Value) {
+	sinfo, err := getStructInfo(in.Type())
+	if err != nil {
+		panic(err)
+	}
+	e.mappingv(tag, func() {
+		for _, info := range sinfo.FieldsList {
+			var value reflect.Value
+			if info.Inline == nil {
+				value = in.Field(info.Num)
+			} else {
+				value = in.FieldByIndex(info.Inline)
+			}
+			if info.OmitEmpty && isZero(value) {
+				continue
+			}
+			e.marshal("", reflect.ValueOf(info.Key))
+			e.flow = info.Flow
+			e.marshal("", value)
+		}
+		if sinfo.InlineMap >= 0 {
+			m := in.Field(sinfo.InlineMap)
+			if m.Len() > 0 {
+				e.flow = false
+				keys := keyList(m.MapKeys())
+				sort.Sort(keys)
+				for _, k := range keys {
+					if _, found := sinfo.FieldsMap[k.String()]; found {
+						panic(fmt.Sprintf("Can't have key %q in inlined map; conflicts with struct field", k.String()))
+					}
+					e.marshal("", k)
+					e.flow = false
+					e.marshal("", m.MapIndex(k))
+				}
+			}
+		}
+	})
+}
+
+func (e *encoder) mappingv(tag string, f func()) {
+	implicit := tag == ""
+	style := yaml_BLOCK_MAPPING_STYLE
+	if e.flow {
+		e.flow = false
+		style = yaml_FLOW_MAPPING_STYLE
+	}
+	yaml_mapping_start_event_initialize(&e.event, nil, []byte(tag), implicit, style)
+	e.emit()
+	f()
+	yaml_mapping_end_event_initialize(&e.event)
+	e.emit()
+}
+
+func (e *encoder) slicev(tag string, in reflect.Value) {
+	implicit := tag == ""
+	style := yaml_BLOCK_SEQUENCE_STYLE
+	if e.flow {
+		e.flow = false
+		style = yaml_FLOW_SEQUENCE_STYLE
+	}
+	e.must(yaml_sequence_start_event_initialize(&e.event, nil, []byte(tag), implicit, style))
+	e.emit()
+	n := in.Len()
+	for i := 0; i < n; i++ {
+		e.marshal("", in.Index(i))
+	}
+	e.must(yaml_sequence_end_event_initialize(&e.event))
+	e.emit()
+}
+
+// isBase60 returns whether s is in base 60 notation as defined in YAML 1.1.
+//
+// The base 60 float notation in YAML 1.1 is a terrible idea and is unsupported
+// in YAML 1.2 and by this package, but these should be marshalled quoted for
+// the time being for compatibility with other parsers.
+func isBase60Float(s string) (result bool) {
+	// Fast path.
+	if s == "" {
+		return false
+	}
+	c := s[0]
+	if !(c == '+' || c == '-' || c >= '0' && c <= '9') || strings.IndexByte(s, ':') < 0 {
+		return false
+	}
+	// Do the full match.
+	return base60float.MatchString(s)
+}
+
+// From http://yaml.org/type/float.html, except the regular expression there
+// is bogus. In practice parsers do not enforce the "\.[0-9_]*" suffix.
+var base60float = regexp.MustCompile(`^[-+]?[0-9][0-9_]*(?::[0-5]?[0-9])+(?:\.[0-9_]*)?$`)
+
+func (e *encoder) stringv(tag string, in reflect.Value) {
+	var style yaml_scalar_style_t
+	s := in.String()
+	canUsePlain := true
+	switch {
+	case !utf8.ValidString(s):
+		if tag == yaml_BINARY_TAG {
+			failf("explicitly tagged !!binary data must be base64-encoded")
+		}
+		if tag != "" {
+			failf("cannot marshal invalid UTF-8 data as %s", shortTag(tag))
+		}
+		// It can't be encoded directly as YAML so use a binary tag
+		// and encode it as base64.
+		tag = yaml_BINARY_TAG
+		s = encodeBase64(s)
+	case tag == "":
+		// Check to see if it would resolve to a specific
+		// tag when encoded unquoted. If it doesn't,
+		// there's no need to quote it.
+		rtag, _ := resolve("", s)
+		canUsePlain = rtag == yaml_STR_TAG && !isBase60Float(s)
+	}
+	// Note: it's possible for user code to emit invalid YAML
+	// if they explicitly specify a tag and a string containing
+	// text that's incompatible with that tag.
+	switch {
+	case strings.Contains(s, "\n"):
+		style = yaml_LITERAL_SCALAR_STYLE
+	case canUsePlain:
+		style = yaml_PLAIN_SCALAR_STYLE
+	default:
+		style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+	}
+	e.emitScalar(s, "", tag, style)
+}
+
+func (e *encoder) boolv(tag string, in reflect.Value) {
+	var s string
+	if in.Bool() {
+		s = "true"
+	} else {
+		s = "false"
+	}
+	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE)
+}
+
+func (e *encoder) intv(tag string, in reflect.Value) {
+	s := strconv.FormatInt(in.Int(), 10)
+	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE)
+}
+
+func (e *encoder) uintv(tag string, in reflect.Value) {
+	s := strconv.FormatUint(in.Uint(), 10)
+	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE)
+}
+
+func (e *encoder) timev(tag string, in reflect.Value) {
+	t := in.Interface().(time.Time)
+	s := t.Format(time.RFC3339Nano)
+	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE)
+}
+
+func (e *encoder) floatv(tag string, in reflect.Value) {
+	// Issue #352: When formatting, use the precision of the underlying value
+	precision := 64
+	if in.Kind() == reflect.Float32 {
+		precision = 32
+	}
+
+	s := strconv.FormatFloat(in.Float(), 'g', -1, precision)
+	switch s {
+	case "+Inf":
+		s = ".inf"
+	case "-Inf":
+		s = "-.inf"
+	case "NaN":
+		s = ".nan"
+	}
+	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE)
+}
+
+func (e *encoder) nilv() {
+	e.emitScalar("null", "", "", yaml_PLAIN_SCALAR_STYLE)
+}
+
+func (e *encoder) emitScalar(value, anchor, tag string, style yaml_scalar_style_t) {
+	implicit := tag == ""
+	e.must(yaml_scalar_event_initialize(&e.event, []byte(anchor), []byte(tag), []byte(value), implicit, implicit, style))
+	e.emit()
+}
diff --git a/vendor/gopkg.in/yaml.v2/go.mod b/vendor/gopkg.in/yaml.v2/go.mod
new file mode 100644
index 0000000..1934e87
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/go.mod
@@ -0,0 +1,5 @@
+module "gopkg.in/yaml.v2"
+
+require (
+	"gopkg.in/check.v1" v0.0.0-20161208181325-20d25e280405
+)
diff --git a/vendor/gopkg.in/yaml.v2/parserc.go b/vendor/gopkg.in/yaml.v2/parserc.go
new file mode 100644
index 0000000..81d05df
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/parserc.go
@@ -0,0 +1,1095 @@
+package yaml
+
+import (
+	"bytes"
+)
+
+// The parser implements the following grammar:
+//
+// stream               ::= STREAM-START implicit_document? explicit_document* STREAM-END
+// implicit_document    ::= block_node DOCUMENT-END*
+// explicit_document    ::= DIRECTIVE* DOCUMENT-START block_node? DOCUMENT-END*
+// block_node_or_indentless_sequence    ::=
+//                          ALIAS
+//                          | properties (block_content | indentless_block_sequence)?
+//                          | block_content
+//                          | indentless_block_sequence
+// block_node           ::= ALIAS
+//                          | properties block_content?
+//                          | block_content
+// flow_node            ::= ALIAS
+//                          | properties flow_content?
+//                          | flow_content
+// properties           ::= TAG ANCHOR? | ANCHOR TAG?
+// block_content        ::= block_collection | flow_collection | SCALAR
+// flow_content         ::= flow_collection | SCALAR
+// block_collection     ::= block_sequence | block_mapping
+// flow_collection      ::= flow_sequence | flow_mapping
+// block_sequence       ::= BLOCK-SEQUENCE-START (BLOCK-ENTRY block_node?)* BLOCK-END
+// indentless_sequence  ::= (BLOCK-ENTRY block_node?)+
+// block_mapping        ::= BLOCK-MAPPING_START
+//                          ((KEY block_node_or_indentless_sequence?)?
+//                          (VALUE block_node_or_indentless_sequence?)?)*
+//                          BLOCK-END
+// flow_sequence        ::= FLOW-SEQUENCE-START
+//                          (flow_sequence_entry FLOW-ENTRY)*
+//                          flow_sequence_entry?
+//                          FLOW-SEQUENCE-END
+// flow_sequence_entry  ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+// flow_mapping         ::= FLOW-MAPPING-START
+//                          (flow_mapping_entry FLOW-ENTRY)*
+//                          flow_mapping_entry?
+//                          FLOW-MAPPING-END
+// flow_mapping_entry   ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+
+// Peek the next token in the token queue.
+func peek_token(parser *yaml_parser_t) *yaml_token_t {
+	if parser.token_available || yaml_parser_fetch_more_tokens(parser) {
+		return &parser.tokens[parser.tokens_head]
+	}
+	return nil
+}
+
+// Remove the next token from the queue (must be called after peek_token).
+func skip_token(parser *yaml_parser_t) {
+	parser.token_available = false
+	parser.tokens_parsed++
+	parser.stream_end_produced = parser.tokens[parser.tokens_head].typ == yaml_STREAM_END_TOKEN
+	parser.tokens_head++
+}
+
+// Get the next event.
+func yaml_parser_parse(parser *yaml_parser_t, event *yaml_event_t) bool {
+	// Erase the event object.
+	*event = yaml_event_t{}
+
+	// No events after the end of the stream or error.
+	if parser.stream_end_produced || parser.error != yaml_NO_ERROR || parser.state == yaml_PARSE_END_STATE {
+		return true
+	}
+
+	// Generate the next event.
+	return yaml_parser_state_machine(parser, event)
+}
+
+// Set parser error.
+func yaml_parser_set_parser_error(parser *yaml_parser_t, problem string, problem_mark yaml_mark_t) bool {
+	parser.error = yaml_PARSER_ERROR
+	parser.problem = problem
+	parser.problem_mark = problem_mark
+	return false
+}
+
+func yaml_parser_set_parser_error_context(parser *yaml_parser_t, context string, context_mark yaml_mark_t, problem string, problem_mark yaml_mark_t) bool {
+	parser.error = yaml_PARSER_ERROR
+	parser.context = context
+	parser.context_mark = context_mark
+	parser.problem = problem
+	parser.problem_mark = problem_mark
+	return false
+}
+
+// State dispatcher.
+func yaml_parser_state_machine(parser *yaml_parser_t, event *yaml_event_t) bool {
+	//trace("yaml_parser_state_machine", "state:", parser.state.String())
+
+	switch parser.state {
+	case yaml_PARSE_STREAM_START_STATE:
+		return yaml_parser_parse_stream_start(parser, event)
+
+	case yaml_PARSE_IMPLICIT_DOCUMENT_START_STATE:
+		return yaml_parser_parse_document_start(parser, event, true)
+
+	case yaml_PARSE_DOCUMENT_START_STATE:
+		return yaml_parser_parse_document_start(parser, event, false)
+
+	case yaml_PARSE_DOCUMENT_CONTENT_STATE:
+		return yaml_parser_parse_document_content(parser, event)
+
+	case yaml_PARSE_DOCUMENT_END_STATE:
+		return yaml_parser_parse_document_end(parser, event)
+
+	case yaml_PARSE_BLOCK_NODE_STATE:
+		return yaml_parser_parse_node(parser, event, true, false)
+
+	case yaml_PARSE_BLOCK_NODE_OR_INDENTLESS_SEQUENCE_STATE:
+		return yaml_parser_parse_node(parser, event, true, true)
+
+	case yaml_PARSE_FLOW_NODE_STATE:
+		return yaml_parser_parse_node(parser, event, false, false)
+
+	case yaml_PARSE_BLOCK_SEQUENCE_FIRST_ENTRY_STATE:
+		return yaml_parser_parse_block_sequence_entry(parser, event, true)
+
+	case yaml_PARSE_BLOCK_SEQUENCE_ENTRY_STATE:
+		return yaml_parser_parse_block_sequence_entry(parser, event, false)
+
+	case yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE:
+		return yaml_parser_parse_indentless_sequence_entry(parser, event)
+
+	case yaml_PARSE_BLOCK_MAPPING_FIRST_KEY_STATE:
+		return yaml_parser_parse_block_mapping_key(parser, event, true)
+
+	case yaml_PARSE_BLOCK_MAPPING_KEY_STATE:
+		return yaml_parser_parse_block_mapping_key(parser, event, false)
+
+	case yaml_PARSE_BLOCK_MAPPING_VALUE_STATE:
+		return yaml_parser_parse_block_mapping_value(parser, event)
+
+	case yaml_PARSE_FLOW_SEQUENCE_FIRST_ENTRY_STATE:
+		return yaml_parser_parse_flow_sequence_entry(parser, event, true)
+
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_STATE:
+		return yaml_parser_parse_flow_sequence_entry(parser, event, false)
+
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_KEY_STATE:
+		return yaml_parser_parse_flow_sequence_entry_mapping_key(parser, event)
+
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_VALUE_STATE:
+		return yaml_parser_parse_flow_sequence_entry_mapping_value(parser, event)
+
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_END_STATE:
+		return yaml_parser_parse_flow_sequence_entry_mapping_end(parser, event)
+
+	case yaml_PARSE_FLOW_MAPPING_FIRST_KEY_STATE:
+		return yaml_parser_parse_flow_mapping_key(parser, event, true)
+
+	case yaml_PARSE_FLOW_MAPPING_KEY_STATE:
+		return yaml_parser_parse_flow_mapping_key(parser, event, false)
+
+	case yaml_PARSE_FLOW_MAPPING_VALUE_STATE:
+		return yaml_parser_parse_flow_mapping_value(parser, event, false)
+
+	case yaml_PARSE_FLOW_MAPPING_EMPTY_VALUE_STATE:
+		return yaml_parser_parse_flow_mapping_value(parser, event, true)
+
+	default:
+		panic("invalid parser state")
+	}
+}
+
+// Parse the production:
+// stream   ::= STREAM-START implicit_document? explicit_document* STREAM-END
+//              ************
+func yaml_parser_parse_stream_start(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if token.typ != yaml_STREAM_START_TOKEN {
+		return yaml_parser_set_parser_error(parser, "did not find expected <stream-start>", token.start_mark)
+	}
+	parser.state = yaml_PARSE_IMPLICIT_DOCUMENT_START_STATE
+	*event = yaml_event_t{
+		typ:        yaml_STREAM_START_EVENT,
+		start_mark: token.start_mark,
+		end_mark:   token.end_mark,
+		encoding:   token.encoding,
+	}
+	skip_token(parser)
+	return true
+}
+
+// Parse the productions:
+// implicit_document    ::= block_node DOCUMENT-END*
+//                          *
+// explicit_document    ::= DIRECTIVE* DOCUMENT-START block_node? DOCUMENT-END*
+//                          *************************
+func yaml_parser_parse_document_start(parser *yaml_parser_t, event *yaml_event_t, implicit bool) bool {
+
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	// Parse extra document end indicators.
+	if !implicit {
+		for token.typ == yaml_DOCUMENT_END_TOKEN {
+			skip_token(parser)
+			token = peek_token(parser)
+			if token == nil {
+				return false
+			}
+		}
+	}
+
+	if implicit && token.typ != yaml_VERSION_DIRECTIVE_TOKEN &&
+		token.typ != yaml_TAG_DIRECTIVE_TOKEN &&
+		token.typ != yaml_DOCUMENT_START_TOKEN &&
+		token.typ != yaml_STREAM_END_TOKEN {
+		// Parse an implicit document.
+		if !yaml_parser_process_directives(parser, nil, nil) {
+			return false
+		}
+		parser.states = append(parser.states, yaml_PARSE_DOCUMENT_END_STATE)
+		parser.state = yaml_PARSE_BLOCK_NODE_STATE
+
+		*event = yaml_event_t{
+			typ:        yaml_DOCUMENT_START_EVENT,
+			start_mark: token.start_mark,
+			end_mark:   token.end_mark,
+		}
+
+	} else if token.typ != yaml_STREAM_END_TOKEN {
+		// Parse an explicit document.
+		var version_directive *yaml_version_directive_t
+		var tag_directives []yaml_tag_directive_t
+		start_mark := token.start_mark
+		if !yaml_parser_process_directives(parser, &version_directive, &tag_directives) {
+			return false
+		}
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_DOCUMENT_START_TOKEN {
+			yaml_parser_set_parser_error(parser,
+				"did not find expected <document start>", token.start_mark)
+			return false
+		}
+		parser.states = append(parser.states, yaml_PARSE_DOCUMENT_END_STATE)
+		parser.state = yaml_PARSE_DOCUMENT_CONTENT_STATE
+		end_mark := token.end_mark
+
+		*event = yaml_event_t{
+			typ:               yaml_DOCUMENT_START_EVENT,
+			start_mark:        start_mark,
+			end_mark:          end_mark,
+			version_directive: version_directive,
+			tag_directives:    tag_directives,
+			implicit:          false,
+		}
+		skip_token(parser)
+
+	} else {
+		// Parse the stream end.
+		parser.state = yaml_PARSE_END_STATE
+		*event = yaml_event_t{
+			typ:        yaml_STREAM_END_EVENT,
+			start_mark: token.start_mark,
+			end_mark:   token.end_mark,
+		}
+		skip_token(parser)
+	}
+
+	return true
+}
+
+// Parse the productions:
+// explicit_document    ::= DIRECTIVE* DOCUMENT-START block_node? DOCUMENT-END*
+//                                                    ***********
+//
+func yaml_parser_parse_document_content(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if token.typ == yaml_VERSION_DIRECTIVE_TOKEN ||
+		token.typ == yaml_TAG_DIRECTIVE_TOKEN ||
+		token.typ == yaml_DOCUMENT_START_TOKEN ||
+		token.typ == yaml_DOCUMENT_END_TOKEN ||
+		token.typ == yaml_STREAM_END_TOKEN {
+		parser.state = parser.states[len(parser.states)-1]
+		parser.states = parser.states[:len(parser.states)-1]
+		return yaml_parser_process_empty_scalar(parser, event,
+			token.start_mark)
+	}
+	return yaml_parser_parse_node(parser, event, true, false)
+}
+
+// Parse the productions:
+// implicit_document    ::= block_node DOCUMENT-END*
+//                                     *************
+// explicit_document    ::= DIRECTIVE* DOCUMENT-START block_node? DOCUMENT-END*
+//
+func yaml_parser_parse_document_end(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	start_mark := token.start_mark
+	end_mark := token.start_mark
+
+	implicit := true
+	if token.typ == yaml_DOCUMENT_END_TOKEN {
+		end_mark = token.end_mark
+		skip_token(parser)
+		implicit = false
+	}
+
+	parser.tag_directives = parser.tag_directives[:0]
+
+	parser.state = yaml_PARSE_DOCUMENT_START_STATE
+	*event = yaml_event_t{
+		typ:        yaml_DOCUMENT_END_EVENT,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+		implicit:   implicit,
+	}
+	return true
+}
+
+// Parse the productions:
+// block_node_or_indentless_sequence    ::=
+//                          ALIAS
+//                          *****
+//                          | properties (block_content | indentless_block_sequence)?
+//                            **********  *
+//                          | block_content | indentless_block_sequence
+//                            *
+// block_node           ::= ALIAS
+//                          *****
+//                          | properties block_content?
+//                            ********** *
+//                          | block_content
+//                            *
+// flow_node            ::= ALIAS
+//                          *****
+//                          | properties flow_content?
+//                            ********** *
+//                          | flow_content
+//                            *
+// properties           ::= TAG ANCHOR? | ANCHOR TAG?
+//                          *************************
+// block_content        ::= block_collection | flow_collection | SCALAR
+//                                                               ******
+// flow_content         ::= flow_collection | SCALAR
+//                                            ******
+func yaml_parser_parse_node(parser *yaml_parser_t, event *yaml_event_t, block, indentless_sequence bool) bool {
+	//defer trace("yaml_parser_parse_node", "block:", block, "indentless_sequence:", indentless_sequence)()
+
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	if token.typ == yaml_ALIAS_TOKEN {
+		parser.state = parser.states[len(parser.states)-1]
+		parser.states = parser.states[:len(parser.states)-1]
+		*event = yaml_event_t{
+			typ:        yaml_ALIAS_EVENT,
+			start_mark: token.start_mark,
+			end_mark:   token.end_mark,
+			anchor:     token.value,
+		}
+		skip_token(parser)
+		return true
+	}
+
+	start_mark := token.start_mark
+	end_mark := token.start_mark
+
+	var tag_token bool
+	var tag_handle, tag_suffix, anchor []byte
+	var tag_mark yaml_mark_t
+	if token.typ == yaml_ANCHOR_TOKEN {
+		anchor = token.value
+		start_mark = token.start_mark
+		end_mark = token.end_mark
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ == yaml_TAG_TOKEN {
+			tag_token = true
+			tag_handle = token.value
+			tag_suffix = token.suffix
+			tag_mark = token.start_mark
+			end_mark = token.end_mark
+			skip_token(parser)
+			token = peek_token(parser)
+			if token == nil {
+				return false
+			}
+		}
+	} else if token.typ == yaml_TAG_TOKEN {
+		tag_token = true
+		tag_handle = token.value
+		tag_suffix = token.suffix
+		start_mark = token.start_mark
+		tag_mark = token.start_mark
+		end_mark = token.end_mark
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ == yaml_ANCHOR_TOKEN {
+			anchor = token.value
+			end_mark = token.end_mark
+			skip_token(parser)
+			token = peek_token(parser)
+			if token == nil {
+				return false
+			}
+		}
+	}
+
+	var tag []byte
+	if tag_token {
+		if len(tag_handle) == 0 {
+			tag = tag_suffix
+			tag_suffix = nil
+		} else {
+			for i := range parser.tag_directives {
+				if bytes.Equal(parser.tag_directives[i].handle, tag_handle) {
+					tag = append([]byte(nil), parser.tag_directives[i].prefix...)
+					tag = append(tag, tag_suffix...)
+					break
+				}
+			}
+			if len(tag) == 0 {
+				yaml_parser_set_parser_error_context(parser,
+					"while parsing a node", start_mark,
+					"found undefined tag handle", tag_mark)
+				return false
+			}
+		}
+	}
+
+	implicit := len(tag) == 0
+	if indentless_sequence && token.typ == yaml_BLOCK_ENTRY_TOKEN {
+		end_mark = token.end_mark
+		parser.state = yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE
+		*event = yaml_event_t{
+			typ:        yaml_SEQUENCE_START_EVENT,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			anchor:     anchor,
+			tag:        tag,
+			implicit:   implicit,
+			style:      yaml_style_t(yaml_BLOCK_SEQUENCE_STYLE),
+		}
+		return true
+	}
+	if token.typ == yaml_SCALAR_TOKEN {
+		var plain_implicit, quoted_implicit bool
+		end_mark = token.end_mark
+		if (len(tag) == 0 && token.style == yaml_PLAIN_SCALAR_STYLE) || (len(tag) == 1 && tag[0] == '!') {
+			plain_implicit = true
+		} else if len(tag) == 0 {
+			quoted_implicit = true
+		}
+		parser.state = parser.states[len(parser.states)-1]
+		parser.states = parser.states[:len(parser.states)-1]
+
+		*event = yaml_event_t{
+			typ:             yaml_SCALAR_EVENT,
+			start_mark:      start_mark,
+			end_mark:        end_mark,
+			anchor:          anchor,
+			tag:             tag,
+			value:           token.value,
+			implicit:        plain_implicit,
+			quoted_implicit: quoted_implicit,
+			style:           yaml_style_t(token.style),
+		}
+		skip_token(parser)
+		return true
+	}
+	if token.typ == yaml_FLOW_SEQUENCE_START_TOKEN {
+		// [Go] Some of the events below can be merged as they differ only on style.
+		end_mark = token.end_mark
+		parser.state = yaml_PARSE_FLOW_SEQUENCE_FIRST_ENTRY_STATE
+		*event = yaml_event_t{
+			typ:        yaml_SEQUENCE_START_EVENT,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			anchor:     anchor,
+			tag:        tag,
+			implicit:   implicit,
+			style:      yaml_style_t(yaml_FLOW_SEQUENCE_STYLE),
+		}
+		return true
+	}
+	if token.typ == yaml_FLOW_MAPPING_START_TOKEN {
+		end_mark = token.end_mark
+		parser.state = yaml_PARSE_FLOW_MAPPING_FIRST_KEY_STATE
+		*event = yaml_event_t{
+			typ:        yaml_MAPPING_START_EVENT,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			anchor:     anchor,
+			tag:        tag,
+			implicit:   implicit,
+			style:      yaml_style_t(yaml_FLOW_MAPPING_STYLE),
+		}
+		return true
+	}
+	if block && token.typ == yaml_BLOCK_SEQUENCE_START_TOKEN {
+		end_mark = token.end_mark
+		parser.state = yaml_PARSE_BLOCK_SEQUENCE_FIRST_ENTRY_STATE
+		*event = yaml_event_t{
+			typ:        yaml_SEQUENCE_START_EVENT,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			anchor:     anchor,
+			tag:        tag,
+			implicit:   implicit,
+			style:      yaml_style_t(yaml_BLOCK_SEQUENCE_STYLE),
+		}
+		return true
+	}
+	if block && token.typ == yaml_BLOCK_MAPPING_START_TOKEN {
+		end_mark = token.end_mark
+		parser.state = yaml_PARSE_BLOCK_MAPPING_FIRST_KEY_STATE
+		*event = yaml_event_t{
+			typ:        yaml_MAPPING_START_EVENT,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			anchor:     anchor,
+			tag:        tag,
+			implicit:   implicit,
+			style:      yaml_style_t(yaml_BLOCK_MAPPING_STYLE),
+		}
+		return true
+	}
+	if len(anchor) > 0 || len(tag) > 0 {
+		parser.state = parser.states[len(parser.states)-1]
+		parser.states = parser.states[:len(parser.states)-1]
+
+		*event = yaml_event_t{
+			typ:             yaml_SCALAR_EVENT,
+			start_mark:      start_mark,
+			end_mark:        end_mark,
+			anchor:          anchor,
+			tag:             tag,
+			implicit:        implicit,
+			quoted_implicit: false,
+			style:           yaml_style_t(yaml_PLAIN_SCALAR_STYLE),
+		}
+		return true
+	}
+
+	context := "while parsing a flow node"
+	if block {
+		context = "while parsing a block node"
+	}
+	yaml_parser_set_parser_error_context(parser, context, start_mark,
+		"did not find expected node content", token.start_mark)
+	return false
+}
+
+// Parse the productions:
+// block_sequence ::= BLOCK-SEQUENCE-START (BLOCK-ENTRY block_node?)* BLOCK-END
+//                    ********************  *********** *             *********
+//
+func yaml_parser_parse_block_sequence_entry(parser *yaml_parser_t, event *yaml_event_t, first bool) bool {
+	if first {
+		token := peek_token(parser)
+		parser.marks = append(parser.marks, token.start_mark)
+		skip_token(parser)
+	}
+
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	if token.typ == yaml_BLOCK_ENTRY_TOKEN {
+		mark := token.end_mark
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_BLOCK_ENTRY_TOKEN && token.typ != yaml_BLOCK_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_BLOCK_SEQUENCE_ENTRY_STATE)
+			return yaml_parser_parse_node(parser, event, true, false)
+		} else {
+			parser.state = yaml_PARSE_BLOCK_SEQUENCE_ENTRY_STATE
+			return yaml_parser_process_empty_scalar(parser, event, mark)
+		}
+	}
+	if token.typ == yaml_BLOCK_END_TOKEN {
+		parser.state = parser.states[len(parser.states)-1]
+		parser.states = parser.states[:len(parser.states)-1]
+		parser.marks = parser.marks[:len(parser.marks)-1]
+
+		*event = yaml_event_t{
+			typ:        yaml_SEQUENCE_END_EVENT,
+			start_mark: token.start_mark,
+			end_mark:   token.end_mark,
+		}
+
+		skip_token(parser)
+		return true
+	}
+
+	context_mark := parser.marks[len(parser.marks)-1]
+	parser.marks = parser.marks[:len(parser.marks)-1]
+	return yaml_parser_set_parser_error_context(parser,
+		"while parsing a block collection", context_mark,
+		"did not find expected '-' indicator", token.start_mark)
+}
+
+// Parse the productions:
+// indentless_sequence  ::= (BLOCK-ENTRY block_node?)+
+//                           *********** *
+func yaml_parser_parse_indentless_sequence_entry(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	if token.typ == yaml_BLOCK_ENTRY_TOKEN {
+		mark := token.end_mark
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_BLOCK_ENTRY_TOKEN &&
+			token.typ != yaml_KEY_TOKEN &&
+			token.typ != yaml_VALUE_TOKEN &&
+			token.typ != yaml_BLOCK_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE)
+			return yaml_parser_parse_node(parser, event, true, false)
+		}
+		parser.state = yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE
+		return yaml_parser_process_empty_scalar(parser, event, mark)
+	}
+	parser.state = parser.states[len(parser.states)-1]
+	parser.states = parser.states[:len(parser.states)-1]
+
+	*event = yaml_event_t{
+		typ:        yaml_SEQUENCE_END_EVENT,
+		start_mark: token.start_mark,
+		end_mark:   token.start_mark, // [Go] Shouldn't this be token.end_mark?
+	}
+	return true
+}
+
+// Parse the productions:
+// block_mapping        ::= BLOCK-MAPPING_START
+//                          *******************
+//                          ((KEY block_node_or_indentless_sequence?)?
+//                            *** *
+//                          (VALUE block_node_or_indentless_sequence?)?)*
+//
+//                          BLOCK-END
+//                          *********
+//
+func yaml_parser_parse_block_mapping_key(parser *yaml_parser_t, event *yaml_event_t, first bool) bool {
+	if first {
+		token := peek_token(parser)
+		parser.marks = append(parser.marks, token.start_mark)
+		skip_token(parser)
+	}
+
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	if token.typ == yaml_KEY_TOKEN {
+		mark := token.end_mark
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_KEY_TOKEN &&
+			token.typ != yaml_VALUE_TOKEN &&
+			token.typ != yaml_BLOCK_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_BLOCK_MAPPING_VALUE_STATE)
+			return yaml_parser_parse_node(parser, event, true, true)
+		} else {
+			parser.state = yaml_PARSE_BLOCK_MAPPING_VALUE_STATE
+			return yaml_parser_process_empty_scalar(parser, event, mark)
+		}
+	} else if token.typ == yaml_BLOCK_END_TOKEN {
+		parser.state = parser.states[len(parser.states)-1]
+		parser.states = parser.states[:len(parser.states)-1]
+		parser.marks = parser.marks[:len(parser.marks)-1]
+		*event = yaml_event_t{
+			typ:        yaml_MAPPING_END_EVENT,
+			start_mark: token.start_mark,
+			end_mark:   token.end_mark,
+		}
+		skip_token(parser)
+		return true
+	}
+
+	context_mark := parser.marks[len(parser.marks)-1]
+	parser.marks = parser.marks[:len(parser.marks)-1]
+	return yaml_parser_set_parser_error_context(parser,
+		"while parsing a block mapping", context_mark,
+		"did not find expected key", token.start_mark)
+}
+
+// Parse the productions:
+// block_mapping        ::= BLOCK-MAPPING_START
+//
+//                          ((KEY block_node_or_indentless_sequence?)?
+//
+//                          (VALUE block_node_or_indentless_sequence?)?)*
+//                           ***** *
+//                          BLOCK-END
+//
+//
+func yaml_parser_parse_block_mapping_value(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if token.typ == yaml_VALUE_TOKEN {
+		mark := token.end_mark
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_KEY_TOKEN &&
+			token.typ != yaml_VALUE_TOKEN &&
+			token.typ != yaml_BLOCK_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_BLOCK_MAPPING_KEY_STATE)
+			return yaml_parser_parse_node(parser, event, true, true)
+		}
+		parser.state = yaml_PARSE_BLOCK_MAPPING_KEY_STATE
+		return yaml_parser_process_empty_scalar(parser, event, mark)
+	}
+	parser.state = yaml_PARSE_BLOCK_MAPPING_KEY_STATE
+	return yaml_parser_process_empty_scalar(parser, event, token.start_mark)
+}
+
+// Parse the productions:
+// flow_sequence        ::= FLOW-SEQUENCE-START
+//                          *******************
+//                          (flow_sequence_entry FLOW-ENTRY)*
+//                           *                   **********
+//                          flow_sequence_entry?
+//                          *
+//                          FLOW-SEQUENCE-END
+//                          *****************
+// flow_sequence_entry  ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+//                          *
+//
+func yaml_parser_parse_flow_sequence_entry(parser *yaml_parser_t, event *yaml_event_t, first bool) bool {
+	if first {
+		token := peek_token(parser)
+		parser.marks = append(parser.marks, token.start_mark)
+		skip_token(parser)
+	}
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if token.typ != yaml_FLOW_SEQUENCE_END_TOKEN {
+		if !first {
+			if token.typ == yaml_FLOW_ENTRY_TOKEN {
+				skip_token(parser)
+				token = peek_token(parser)
+				if token == nil {
+					return false
+				}
+			} else {
+				context_mark := parser.marks[len(parser.marks)-1]
+				parser.marks = parser.marks[:len(parser.marks)-1]
+				return yaml_parser_set_parser_error_context(parser,
+					"while parsing a flow sequence", context_mark,
+					"did not find expected ',' or ']'", token.start_mark)
+			}
+		}
+
+		if token.typ == yaml_KEY_TOKEN {
+			parser.state = yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_KEY_STATE
+			*event = yaml_event_t{
+				typ:        yaml_MAPPING_START_EVENT,
+				start_mark: token.start_mark,
+				end_mark:   token.end_mark,
+				implicit:   true,
+				style:      yaml_style_t(yaml_FLOW_MAPPING_STYLE),
+			}
+			skip_token(parser)
+			return true
+		} else if token.typ != yaml_FLOW_SEQUENCE_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_FLOW_SEQUENCE_ENTRY_STATE)
+			return yaml_parser_parse_node(parser, event, false, false)
+		}
+	}
+
+	parser.state = parser.states[len(parser.states)-1]
+	parser.states = parser.states[:len(parser.states)-1]
+	parser.marks = parser.marks[:len(parser.marks)-1]
+
+	*event = yaml_event_t{
+		typ:        yaml_SEQUENCE_END_EVENT,
+		start_mark: token.start_mark,
+		end_mark:   token.end_mark,
+	}
+
+	skip_token(parser)
+	return true
+}
+
+//
+// Parse the productions:
+// flow_sequence_entry  ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+//                                      *** *
+//
+func yaml_parser_parse_flow_sequence_entry_mapping_key(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if token.typ != yaml_VALUE_TOKEN &&
+		token.typ != yaml_FLOW_ENTRY_TOKEN &&
+		token.typ != yaml_FLOW_SEQUENCE_END_TOKEN {
+		parser.states = append(parser.states, yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_VALUE_STATE)
+		return yaml_parser_parse_node(parser, event, false, false)
+	}
+	mark := token.end_mark
+	skip_token(parser)
+	parser.state = yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_VALUE_STATE
+	return yaml_parser_process_empty_scalar(parser, event, mark)
+}
+
+// Parse the productions:
+// flow_sequence_entry  ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+//                                                      ***** *
+//
+func yaml_parser_parse_flow_sequence_entry_mapping_value(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if token.typ == yaml_VALUE_TOKEN {
+		skip_token(parser)
+		token := peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_FLOW_ENTRY_TOKEN && token.typ != yaml_FLOW_SEQUENCE_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_END_STATE)
+			return yaml_parser_parse_node(parser, event, false, false)
+		}
+	}
+	parser.state = yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_END_STATE
+	return yaml_parser_process_empty_scalar(parser, event, token.start_mark)
+}
+
+// Parse the productions:
+// flow_sequence_entry  ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+//                                                                      *
+//
+func yaml_parser_parse_flow_sequence_entry_mapping_end(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	parser.state = yaml_PARSE_FLOW_SEQUENCE_ENTRY_STATE
+	*event = yaml_event_t{
+		typ:        yaml_MAPPING_END_EVENT,
+		start_mark: token.start_mark,
+		end_mark:   token.start_mark, // [Go] Shouldn't this be end_mark?
+	}
+	return true
+}
+
+// Parse the productions:
+// flow_mapping         ::= FLOW-MAPPING-START
+//                          ******************
+//                          (flow_mapping_entry FLOW-ENTRY)*
+//                           *                  **********
+//                          flow_mapping_entry?
+//                          ******************
+//                          FLOW-MAPPING-END
+//                          ****************
+// flow_mapping_entry   ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+//                          *           *** *
+//
+func yaml_parser_parse_flow_mapping_key(parser *yaml_parser_t, event *yaml_event_t, first bool) bool {
+	if first {
+		token := peek_token(parser)
+		parser.marks = append(parser.marks, token.start_mark)
+		skip_token(parser)
+	}
+
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	if token.typ != yaml_FLOW_MAPPING_END_TOKEN {
+		if !first {
+			if token.typ == yaml_FLOW_ENTRY_TOKEN {
+				skip_token(parser)
+				token = peek_token(parser)
+				if token == nil {
+					return false
+				}
+			} else {
+				context_mark := parser.marks[len(parser.marks)-1]
+				parser.marks = parser.marks[:len(parser.marks)-1]
+				return yaml_parser_set_parser_error_context(parser,
+					"while parsing a flow mapping", context_mark,
+					"did not find expected ',' or '}'", token.start_mark)
+			}
+		}
+
+		if token.typ == yaml_KEY_TOKEN {
+			skip_token(parser)
+			token = peek_token(parser)
+			if token == nil {
+				return false
+			}
+			if token.typ != yaml_VALUE_TOKEN &&
+				token.typ != yaml_FLOW_ENTRY_TOKEN &&
+				token.typ != yaml_FLOW_MAPPING_END_TOKEN {
+				parser.states = append(parser.states, yaml_PARSE_FLOW_MAPPING_VALUE_STATE)
+				return yaml_parser_parse_node(parser, event, false, false)
+			} else {
+				parser.state = yaml_PARSE_FLOW_MAPPING_VALUE_STATE
+				return yaml_parser_process_empty_scalar(parser, event, token.start_mark)
+			}
+		} else if token.typ != yaml_FLOW_MAPPING_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_FLOW_MAPPING_EMPTY_VALUE_STATE)
+			return yaml_parser_parse_node(parser, event, false, false)
+		}
+	}
+
+	parser.state = parser.states[len(parser.states)-1]
+	parser.states = parser.states[:len(parser.states)-1]
+	parser.marks = parser.marks[:len(parser.marks)-1]
+	*event = yaml_event_t{
+		typ:        yaml_MAPPING_END_EVENT,
+		start_mark: token.start_mark,
+		end_mark:   token.end_mark,
+	}
+	skip_token(parser)
+	return true
+}
+
+// Parse the productions:
+// flow_mapping_entry   ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+//                                   *                  ***** *
+//
+func yaml_parser_parse_flow_mapping_value(parser *yaml_parser_t, event *yaml_event_t, empty bool) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if empty {
+		parser.state = yaml_PARSE_FLOW_MAPPING_KEY_STATE
+		return yaml_parser_process_empty_scalar(parser, event, token.start_mark)
+	}
+	if token.typ == yaml_VALUE_TOKEN {
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_FLOW_ENTRY_TOKEN && token.typ != yaml_FLOW_MAPPING_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_FLOW_MAPPING_KEY_STATE)
+			return yaml_parser_parse_node(parser, event, false, false)
+		}
+	}
+	parser.state = yaml_PARSE_FLOW_MAPPING_KEY_STATE
+	return yaml_parser_process_empty_scalar(parser, event, token.start_mark)
+}
+
+// Generate an empty scalar event.
+func yaml_parser_process_empty_scalar(parser *yaml_parser_t, event *yaml_event_t, mark yaml_mark_t) bool {
+	*event = yaml_event_t{
+		typ:        yaml_SCALAR_EVENT,
+		start_mark: mark,
+		end_mark:   mark,
+		value:      nil, // Empty
+		implicit:   true,
+		style:      yaml_style_t(yaml_PLAIN_SCALAR_STYLE),
+	}
+	return true
+}
+
+var default_tag_directives = []yaml_tag_directive_t{
+	{[]byte("!"), []byte("!")},
+	{[]byte("!!"), []byte("tag:yaml.org,2002:")},
+}
+
+// Parse directives.
+func yaml_parser_process_directives(parser *yaml_parser_t,
+	version_directive_ref **yaml_version_directive_t,
+	tag_directives_ref *[]yaml_tag_directive_t) bool {
+
+	var version_directive *yaml_version_directive_t
+	var tag_directives []yaml_tag_directive_t
+
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	for token.typ == yaml_VERSION_DIRECTIVE_TOKEN || token.typ == yaml_TAG_DIRECTIVE_TOKEN {
+		if token.typ == yaml_VERSION_DIRECTIVE_TOKEN {
+			if version_directive != nil {
+				yaml_parser_set_parser_error(parser,
+					"found duplicate %YAML directive", token.start_mark)
+				return false
+			}
+			if token.major != 1 || token.minor != 1 {
+				yaml_parser_set_parser_error(parser,
+					"found incompatible YAML document", token.start_mark)
+				return false
+			}
+			version_directive = &yaml_version_directive_t{
+				major: token.major,
+				minor: token.minor,
+			}
+		} else if token.typ == yaml_TAG_DIRECTIVE_TOKEN {
+			value := yaml_tag_directive_t{
+				handle: token.value,
+				prefix: token.prefix,
+			}
+			if !yaml_parser_append_tag_directive(parser, value, false, token.start_mark) {
+				return false
+			}
+			tag_directives = append(tag_directives, value)
+		}
+
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+	}
+
+	for i := range default_tag_directives {
+		if !yaml_parser_append_tag_directive(parser, default_tag_directives[i], true, token.start_mark) {
+			return false
+		}
+	}
+
+	if version_directive_ref != nil {
+		*version_directive_ref = version_directive
+	}
+	if tag_directives_ref != nil {
+		*tag_directives_ref = tag_directives
+	}
+	return true
+}
+
+// Append a tag directive to the directives stack.
+func yaml_parser_append_tag_directive(parser *yaml_parser_t, value yaml_tag_directive_t, allow_duplicates bool, mark yaml_mark_t) bool {
+	for i := range parser.tag_directives {
+		if bytes.Equal(value.handle, parser.tag_directives[i].handle) {
+			if allow_duplicates {
+				return true
+			}
+			return yaml_parser_set_parser_error(parser, "found duplicate %TAG directive", mark)
+		}
+	}
+
+	// [Go] I suspect the copy is unnecessary. This was likely done
+	// because there was no way to track ownership of the data.
+	value_copy := yaml_tag_directive_t{
+		handle: make([]byte, len(value.handle)),
+		prefix: make([]byte, len(value.prefix)),
+	}
+	copy(value_copy.handle, value.handle)
+	copy(value_copy.prefix, value.prefix)
+	parser.tag_directives = append(parser.tag_directives, value_copy)
+	return true
+}
diff --git a/vendor/gopkg.in/yaml.v2/readerc.go b/vendor/gopkg.in/yaml.v2/readerc.go
new file mode 100644
index 0000000..7c1f5fa
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/readerc.go
@@ -0,0 +1,412 @@
+package yaml
+
+import (
+	"io"
+)
+
+// Set the reader error and return 0.
+func yaml_parser_set_reader_error(parser *yaml_parser_t, problem string, offset int, value int) bool {
+	parser.error = yaml_READER_ERROR
+	parser.problem = problem
+	parser.problem_offset = offset
+	parser.problem_value = value
+	return false
+}
+
+// Byte order marks.
+const (
+	bom_UTF8    = "\xef\xbb\xbf"
+	bom_UTF16LE = "\xff\xfe"
+	bom_UTF16BE = "\xfe\xff"
+)
+
+// Determine the input stream encoding by checking the BOM symbol. If no BOM is
+// found, the UTF-8 encoding is assumed. Return 1 on success, 0 on failure.
+func yaml_parser_determine_encoding(parser *yaml_parser_t) bool {
+	// Ensure that we had enough bytes in the raw buffer.
+	for !parser.eof && len(parser.raw_buffer)-parser.raw_buffer_pos < 3 {
+		if !yaml_parser_update_raw_buffer(parser) {
+			return false
+		}
+	}
+
+	// Determine the encoding.
+	buf := parser.raw_buffer
+	pos := parser.raw_buffer_pos
+	avail := len(buf) - pos
+	if avail >= 2 && buf[pos] == bom_UTF16LE[0] && buf[pos+1] == bom_UTF16LE[1] {
+		parser.encoding = yaml_UTF16LE_ENCODING
+		parser.raw_buffer_pos += 2
+		parser.offset += 2
+	} else if avail >= 2 && buf[pos] == bom_UTF16BE[0] && buf[pos+1] == bom_UTF16BE[1] {
+		parser.encoding = yaml_UTF16BE_ENCODING
+		parser.raw_buffer_pos += 2
+		parser.offset += 2
+	} else if avail >= 3 && buf[pos] == bom_UTF8[0] && buf[pos+1] == bom_UTF8[1] && buf[pos+2] == bom_UTF8[2] {
+		parser.encoding = yaml_UTF8_ENCODING
+		parser.raw_buffer_pos += 3
+		parser.offset += 3
+	} else {
+		parser.encoding = yaml_UTF8_ENCODING
+	}
+	return true
+}
+
+// Update the raw buffer.
+func yaml_parser_update_raw_buffer(parser *yaml_parser_t) bool {
+	size_read := 0
+
+	// Return if the raw buffer is full.
+	if parser.raw_buffer_pos == 0 && len(parser.raw_buffer) == cap(parser.raw_buffer) {
+		return true
+	}
+
+	// Return on EOF.
+	if parser.eof {
+		return true
+	}
+
+	// Move the remaining bytes in the raw buffer to the beginning.
+	if parser.raw_buffer_pos > 0 && parser.raw_buffer_pos < len(parser.raw_buffer) {
+		copy(parser.raw_buffer, parser.raw_buffer[parser.raw_buffer_pos:])
+	}
+	parser.raw_buffer = parser.raw_buffer[:len(parser.raw_buffer)-parser.raw_buffer_pos]
+	parser.raw_buffer_pos = 0
+
+	// Call the read handler to fill the buffer.
+	size_read, err := parser.read_handler(parser, parser.raw_buffer[len(parser.raw_buffer):cap(parser.raw_buffer)])
+	parser.raw_buffer = parser.raw_buffer[:len(parser.raw_buffer)+size_read]
+	if err == io.EOF {
+		parser.eof = true
+	} else if err != nil {
+		return yaml_parser_set_reader_error(parser, "input error: "+err.Error(), parser.offset, -1)
+	}
+	return true
+}
+
+// Ensure that the buffer contains at least `length` characters.
+// Return true on success, false on failure.
+//
+// The length is supposed to be significantly less that the buffer size.
+func yaml_parser_update_buffer(parser *yaml_parser_t, length int) bool {
+	if parser.read_handler == nil {
+		panic("read handler must be set")
+	}
+
+	// [Go] This function was changed to guarantee the requested length size at EOF.
+	// The fact we need to do this is pretty awful, but the description above implies
+	// for that to be the case, and there are tests 
+
+	// If the EOF flag is set and the raw buffer is empty, do nothing.
+	if parser.eof && parser.raw_buffer_pos == len(parser.raw_buffer) {
+		// [Go] ACTUALLY! Read the documentation of this function above.
+		// This is just broken. To return true, we need to have the
+		// given length in the buffer. Not doing that means every single
+		// check that calls this function to make sure the buffer has a
+		// given length is Go) panicking; or C) accessing invalid memory.
+		//return true
+	}
+
+	// Return if the buffer contains enough characters.
+	if parser.unread >= length {
+		return true
+	}
+
+	// Determine the input encoding if it is not known yet.
+	if parser.encoding == yaml_ANY_ENCODING {
+		if !yaml_parser_determine_encoding(parser) {
+			return false
+		}
+	}
+
+	// Move the unread characters to the beginning of the buffer.
+	buffer_len := len(parser.buffer)
+	if parser.buffer_pos > 0 && parser.buffer_pos < buffer_len {
+		copy(parser.buffer, parser.buffer[parser.buffer_pos:])
+		buffer_len -= parser.buffer_pos
+		parser.buffer_pos = 0
+	} else if parser.buffer_pos == buffer_len {
+		buffer_len = 0
+		parser.buffer_pos = 0
+	}
+
+	// Open the whole buffer for writing, and cut it before returning.
+	parser.buffer = parser.buffer[:cap(parser.buffer)]
+
+	// Fill the buffer until it has enough characters.
+	first := true
+	for parser.unread < length {
+
+		// Fill the raw buffer if necessary.
+		if !first || parser.raw_buffer_pos == len(parser.raw_buffer) {
+			if !yaml_parser_update_raw_buffer(parser) {
+				parser.buffer = parser.buffer[:buffer_len]
+				return false
+			}
+		}
+		first = false
+
+		// Decode the raw buffer.
+	inner:
+		for parser.raw_buffer_pos != len(parser.raw_buffer) {
+			var value rune
+			var width int
+
+			raw_unread := len(parser.raw_buffer) - parser.raw_buffer_pos
+
+			// Decode the next character.
+			switch parser.encoding {
+			case yaml_UTF8_ENCODING:
+				// Decode a UTF-8 character.  Check RFC 3629
+				// (http://www.ietf.org/rfc/rfc3629.txt) for more details.
+				//
+				// The following table (taken from the RFC) is used for
+				// decoding.
+				//
+				//    Char. number range |        UTF-8 octet sequence
+				//      (hexadecimal)    |              (binary)
+				//   --------------------+------------------------------------
+				//   0000 0000-0000 007F | 0xxxxxxx
+				//   0000 0080-0000 07FF | 110xxxxx 10xxxxxx
+				//   0000 0800-0000 FFFF | 1110xxxx 10xxxxxx 10xxxxxx
+				//   0001 0000-0010 FFFF | 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
+				//
+				// Additionally, the characters in the range 0xD800-0xDFFF
+				// are prohibited as they are reserved for use with UTF-16
+				// surrogate pairs.
+
+				// Determine the length of the UTF-8 sequence.
+				octet := parser.raw_buffer[parser.raw_buffer_pos]
+				switch {
+				case octet&0x80 == 0x00:
+					width = 1
+				case octet&0xE0 == 0xC0:
+					width = 2
+				case octet&0xF0 == 0xE0:
+					width = 3
+				case octet&0xF8 == 0xF0:
+					width = 4
+				default:
+					// The leading octet is invalid.
+					return yaml_parser_set_reader_error(parser,
+						"invalid leading UTF-8 octet",
+						parser.offset, int(octet))
+				}
+
+				// Check if the raw buffer contains an incomplete character.
+				if width > raw_unread {
+					if parser.eof {
+						return yaml_parser_set_reader_error(parser,
+							"incomplete UTF-8 octet sequence",
+							parser.offset, -1)
+					}
+					break inner
+				}
+
+				// Decode the leading octet.
+				switch {
+				case octet&0x80 == 0x00:
+					value = rune(octet & 0x7F)
+				case octet&0xE0 == 0xC0:
+					value = rune(octet & 0x1F)
+				case octet&0xF0 == 0xE0:
+					value = rune(octet & 0x0F)
+				case octet&0xF8 == 0xF0:
+					value = rune(octet & 0x07)
+				default:
+					value = 0
+				}
+
+				// Check and decode the trailing octets.
+				for k := 1; k < width; k++ {
+					octet = parser.raw_buffer[parser.raw_buffer_pos+k]
+
+					// Check if the octet is valid.
+					if (octet & 0xC0) != 0x80 {
+						return yaml_parser_set_reader_error(parser,
+							"invalid trailing UTF-8 octet",
+							parser.offset+k, int(octet))
+					}
+
+					// Decode the octet.
+					value = (value << 6) + rune(octet&0x3F)
+				}
+
+				// Check the length of the sequence against the value.
+				switch {
+				case width == 1:
+				case width == 2 && value >= 0x80:
+				case width == 3 && value >= 0x800:
+				case width == 4 && value >= 0x10000:
+				default:
+					return yaml_parser_set_reader_error(parser,
+						"invalid length of a UTF-8 sequence",
+						parser.offset, -1)
+				}
+
+				// Check the range of the value.
+				if value >= 0xD800 && value <= 0xDFFF || value > 0x10FFFF {
+					return yaml_parser_set_reader_error(parser,
+						"invalid Unicode character",
+						parser.offset, int(value))
+				}
+
+			case yaml_UTF16LE_ENCODING, yaml_UTF16BE_ENCODING:
+				var low, high int
+				if parser.encoding == yaml_UTF16LE_ENCODING {
+					low, high = 0, 1
+				} else {
+					low, high = 1, 0
+				}
+
+				// The UTF-16 encoding is not as simple as one might
+				// naively think.  Check RFC 2781
+				// (http://www.ietf.org/rfc/rfc2781.txt).
+				//
+				// Normally, two subsequent bytes describe a Unicode
+				// character.  However a special technique (called a
+				// surrogate pair) is used for specifying character
+				// values larger than 0xFFFF.
+				//
+				// A surrogate pair consists of two pseudo-characters:
+				//      high surrogate area (0xD800-0xDBFF)
+				//      low surrogate area (0xDC00-0xDFFF)
+				//
+				// The following formulas are used for decoding
+				// and encoding characters using surrogate pairs:
+				//
+				//  U  = U' + 0x10000   (0x01 00 00 <= U <= 0x10 FF FF)
+				//  U' = yyyyyyyyyyxxxxxxxxxx   (0 <= U' <= 0x0F FF FF)
+				//  W1 = 110110yyyyyyyyyy
+				//  W2 = 110111xxxxxxxxxx
+				//
+				// where U is the character value, W1 is the high surrogate
+				// area, W2 is the low surrogate area.
+
+				// Check for incomplete UTF-16 character.
+				if raw_unread < 2 {
+					if parser.eof {
+						return yaml_parser_set_reader_error(parser,
+							"incomplete UTF-16 character",
+							parser.offset, -1)
+					}
+					break inner
+				}
+
+				// Get the character.
+				value = rune(parser.raw_buffer[parser.raw_buffer_pos+low]) +
+					(rune(parser.raw_buffer[parser.raw_buffer_pos+high]) << 8)
+
+				// Check for unexpected low surrogate area.
+				if value&0xFC00 == 0xDC00 {
+					return yaml_parser_set_reader_error(parser,
+						"unexpected low surrogate area",
+						parser.offset, int(value))
+				}
+
+				// Check for a high surrogate area.
+				if value&0xFC00 == 0xD800 {
+					width = 4
+
+					// Check for incomplete surrogate pair.
+					if raw_unread < 4 {
+						if parser.eof {
+							return yaml_parser_set_reader_error(parser,
+								"incomplete UTF-16 surrogate pair",
+								parser.offset, -1)
+						}
+						break inner
+					}
+
+					// Get the next character.
+					value2 := rune(parser.raw_buffer[parser.raw_buffer_pos+low+2]) +
+						(rune(parser.raw_buffer[parser.raw_buffer_pos+high+2]) << 8)
+
+					// Check for a low surrogate area.
+					if value2&0xFC00 != 0xDC00 {
+						return yaml_parser_set_reader_error(parser,
+							"expected low surrogate area",
+							parser.offset+2, int(value2))
+					}
+
+					// Generate the value of the surrogate pair.
+					value = 0x10000 + ((value & 0x3FF) << 10) + (value2 & 0x3FF)
+				} else {
+					width = 2
+				}
+
+			default:
+				panic("impossible")
+			}
+
+			// Check if the character is in the allowed range:
+			//      #x9 | #xA | #xD | [#x20-#x7E]               (8 bit)
+			//      | #x85 | [#xA0-#xD7FF] | [#xE000-#xFFFD]    (16 bit)
+			//      | [#x10000-#x10FFFF]                        (32 bit)
+			switch {
+			case value == 0x09:
+			case value == 0x0A:
+			case value == 0x0D:
+			case value >= 0x20 && value <= 0x7E:
+			case value == 0x85:
+			case value >= 0xA0 && value <= 0xD7FF:
+			case value >= 0xE000 && value <= 0xFFFD:
+			case value >= 0x10000 && value <= 0x10FFFF:
+			default:
+				return yaml_parser_set_reader_error(parser,
+					"control characters are not allowed",
+					parser.offset, int(value))
+			}
+
+			// Move the raw pointers.
+			parser.raw_buffer_pos += width
+			parser.offset += width
+
+			// Finally put the character into the buffer.
+			if value <= 0x7F {
+				// 0000 0000-0000 007F . 0xxxxxxx
+				parser.buffer[buffer_len+0] = byte(value)
+				buffer_len += 1
+			} else if value <= 0x7FF {
+				// 0000 0080-0000 07FF . 110xxxxx 10xxxxxx
+				parser.buffer[buffer_len+0] = byte(0xC0 + (value >> 6))
+				parser.buffer[buffer_len+1] = byte(0x80 + (value & 0x3F))
+				buffer_len += 2
+			} else if value <= 0xFFFF {
+				// 0000 0800-0000 FFFF . 1110xxxx 10xxxxxx 10xxxxxx
+				parser.buffer[buffer_len+0] = byte(0xE0 + (value >> 12))
+				parser.buffer[buffer_len+1] = byte(0x80 + ((value >> 6) & 0x3F))
+				parser.buffer[buffer_len+2] = byte(0x80 + (value & 0x3F))
+				buffer_len += 3
+			} else {
+				// 0001 0000-0010 FFFF . 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
+				parser.buffer[buffer_len+0] = byte(0xF0 + (value >> 18))
+				parser.buffer[buffer_len+1] = byte(0x80 + ((value >> 12) & 0x3F))
+				parser.buffer[buffer_len+2] = byte(0x80 + ((value >> 6) & 0x3F))
+				parser.buffer[buffer_len+3] = byte(0x80 + (value & 0x3F))
+				buffer_len += 4
+			}
+
+			parser.unread++
+		}
+
+		// On EOF, put NUL into the buffer and return.
+		if parser.eof {
+			parser.buffer[buffer_len] = 0
+			buffer_len++
+			parser.unread++
+			break
+		}
+	}
+	// [Go] Read the documentation of this function above. To return true,
+	// we need to have the given length in the buffer. Not doing that means
+	// every single check that calls this function to make sure the buffer
+	// has a given length is Go) panicking; or C) accessing invalid memory.
+	// This happens here due to the EOF above breaking early.
+	for buffer_len < length {
+		parser.buffer[buffer_len] = 0
+		buffer_len++
+	}
+	parser.buffer = parser.buffer[:buffer_len]
+	return true
+}
diff --git a/vendor/gopkg.in/yaml.v2/resolve.go b/vendor/gopkg.in/yaml.v2/resolve.go
new file mode 100644
index 0000000..6c151db
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/resolve.go
@@ -0,0 +1,258 @@
+package yaml
+
+import (
+	"encoding/base64"
+	"math"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type resolveMapItem struct {
+	value interface{}
+	tag   string
+}
+
+var resolveTable = make([]byte, 256)
+var resolveMap = make(map[string]resolveMapItem)
+
+func init() {
+	t := resolveTable
+	t[int('+')] = 'S' // Sign
+	t[int('-')] = 'S'
+	for _, c := range "0123456789" {
+		t[int(c)] = 'D' // Digit
+	}
+	for _, c := range "yYnNtTfFoO~" {
+		t[int(c)] = 'M' // In map
+	}
+	t[int('.')] = '.' // Float (potentially in map)
+
+	var resolveMapList = []struct {
+		v   interface{}
+		tag string
+		l   []string
+	}{
+		{true, yaml_BOOL_TAG, []string{"y", "Y", "yes", "Yes", "YES"}},
+		{true, yaml_BOOL_TAG, []string{"true", "True", "TRUE"}},
+		{true, yaml_BOOL_TAG, []string{"on", "On", "ON"}},
+		{false, yaml_BOOL_TAG, []string{"n", "N", "no", "No", "NO"}},
+		{false, yaml_BOOL_TAG, []string{"false", "False", "FALSE"}},
+		{false, yaml_BOOL_TAG, []string{"off", "Off", "OFF"}},
+		{nil, yaml_NULL_TAG, []string{"", "~", "null", "Null", "NULL"}},
+		{math.NaN(), yaml_FLOAT_TAG, []string{".nan", ".NaN", ".NAN"}},
+		{math.Inf(+1), yaml_FLOAT_TAG, []string{".inf", ".Inf", ".INF"}},
+		{math.Inf(+1), yaml_FLOAT_TAG, []string{"+.inf", "+.Inf", "+.INF"}},
+		{math.Inf(-1), yaml_FLOAT_TAG, []string{"-.inf", "-.Inf", "-.INF"}},
+		{"<<", yaml_MERGE_TAG, []string{"<<"}},
+	}
+
+	m := resolveMap
+	for _, item := range resolveMapList {
+		for _, s := range item.l {
+			m[s] = resolveMapItem{item.v, item.tag}
+		}
+	}
+}
+
+const longTagPrefix = "tag:yaml.org,2002:"
+
+func shortTag(tag string) string {
+	// TODO This can easily be made faster and produce less garbage.
+	if strings.HasPrefix(tag, longTagPrefix) {
+		return "!!" + tag[len(longTagPrefix):]
+	}
+	return tag
+}
+
+func longTag(tag string) string {
+	if strings.HasPrefix(tag, "!!") {
+		return longTagPrefix + tag[2:]
+	}
+	return tag
+}
+
+func resolvableTag(tag string) bool {
+	switch tag {
+	case "", yaml_STR_TAG, yaml_BOOL_TAG, yaml_INT_TAG, yaml_FLOAT_TAG, yaml_NULL_TAG, yaml_TIMESTAMP_TAG:
+		return true
+	}
+	return false
+}
+
+var yamlStyleFloat = regexp.MustCompile(`^[-+]?[0-9]*\.?[0-9]+([eE][-+][0-9]+)?$`)
+
+func resolve(tag string, in string) (rtag string, out interface{}) {
+	if !resolvableTag(tag) {
+		return tag, in
+	}
+
+	defer func() {
+		switch tag {
+		case "", rtag, yaml_STR_TAG, yaml_BINARY_TAG:
+			return
+		case yaml_FLOAT_TAG:
+			if rtag == yaml_INT_TAG {
+				switch v := out.(type) {
+				case int64:
+					rtag = yaml_FLOAT_TAG
+					out = float64(v)
+					return
+				case int:
+					rtag = yaml_FLOAT_TAG
+					out = float64(v)
+					return
+				}
+			}
+		}
+		failf("cannot decode %s `%s` as a %s", shortTag(rtag), in, shortTag(tag))
+	}()
+
+	// Any data is accepted as a !!str or !!binary.
+	// Otherwise, the prefix is enough of a hint about what it might be.
+	hint := byte('N')
+	if in != "" {
+		hint = resolveTable[in[0]]
+	}
+	if hint != 0 && tag != yaml_STR_TAG && tag != yaml_BINARY_TAG {
+		// Handle things we can lookup in a map.
+		if item, ok := resolveMap[in]; ok {
+			return item.tag, item.value
+		}
+
+		// Base 60 floats are a bad idea, were dropped in YAML 1.2, and
+		// are purposefully unsupported here. They're still quoted on
+		// the way out for compatibility with other parser, though.
+
+		switch hint {
+		case 'M':
+			// We've already checked the map above.
+
+		case '.':
+			// Not in the map, so maybe a normal float.
+			floatv, err := strconv.ParseFloat(in, 64)
+			if err == nil {
+				return yaml_FLOAT_TAG, floatv
+			}
+
+		case 'D', 'S':
+			// Int, float, or timestamp.
+			// Only try values as a timestamp if the value is unquoted or there's an explicit
+			// !!timestamp tag.
+			if tag == "" || tag == yaml_TIMESTAMP_TAG {
+				t, ok := parseTimestamp(in)
+				if ok {
+					return yaml_TIMESTAMP_TAG, t
+				}
+			}
+
+			plain := strings.Replace(in, "_", "", -1)
+			intv, err := strconv.ParseInt(plain, 0, 64)
+			if err == nil {
+				if intv == int64(int(intv)) {
+					return yaml_INT_TAG, int(intv)
+				} else {
+					return yaml_INT_TAG, intv
+				}
+			}
+			uintv, err := strconv.ParseUint(plain, 0, 64)
+			if err == nil {
+				return yaml_INT_TAG, uintv
+			}
+			if yamlStyleFloat.MatchString(plain) {
+				floatv, err := strconv.ParseFloat(plain, 64)
+				if err == nil {
+					return yaml_FLOAT_TAG, floatv
+				}
+			}
+			if strings.HasPrefix(plain, "0b") {
+				intv, err := strconv.ParseInt(plain[2:], 2, 64)
+				if err == nil {
+					if intv == int64(int(intv)) {
+						return yaml_INT_TAG, int(intv)
+					} else {
+						return yaml_INT_TAG, intv
+					}
+				}
+				uintv, err := strconv.ParseUint(plain[2:], 2, 64)
+				if err == nil {
+					return yaml_INT_TAG, uintv
+				}
+			} else if strings.HasPrefix(plain, "-0b") {
+				intv, err := strconv.ParseInt("-" + plain[3:], 2, 64)
+				if err == nil {
+					if true || intv == int64(int(intv)) {
+						return yaml_INT_TAG, int(intv)
+					} else {
+						return yaml_INT_TAG, intv
+					}
+				}
+			}
+		default:
+			panic("resolveTable item not yet handled: " + string(rune(hint)) + " (with " + in + ")")
+		}
+	}
+	return yaml_STR_TAG, in
+}
+
+// encodeBase64 encodes s as base64 that is broken up into multiple lines
+// as appropriate for the resulting length.
+func encodeBase64(s string) string {
+	const lineLen = 70
+	encLen := base64.StdEncoding.EncodedLen(len(s))
+	lines := encLen/lineLen + 1
+	buf := make([]byte, encLen*2+lines)
+	in := buf[0:encLen]
+	out := buf[encLen:]
+	base64.StdEncoding.Encode(in, []byte(s))
+	k := 0
+	for i := 0; i < len(in); i += lineLen {
+		j := i + lineLen
+		if j > len(in) {
+			j = len(in)
+		}
+		k += copy(out[k:], in[i:j])
+		if lines > 1 {
+			out[k] = '\n'
+			k++
+		}
+	}
+	return string(out[:k])
+}
+
+// This is a subset of the formats allowed by the regular expression
+// defined at http://yaml.org/type/timestamp.html.
+var allowedTimestampFormats = []string{
+	"2006-1-2T15:4:5.999999999Z07:00", // RCF3339Nano with short date fields.
+	"2006-1-2t15:4:5.999999999Z07:00", // RFC3339Nano with short date fields and lower-case "t".
+	"2006-1-2 15:4:5.999999999",       // space separated with no time zone
+	"2006-1-2",                        // date only
+	// Notable exception: time.Parse cannot handle: "2001-12-14 21:59:43.10 -5"
+	// from the set of examples.
+}
+
+// parseTimestamp parses s as a timestamp string and
+// returns the timestamp and reports whether it succeeded.
+// Timestamp formats are defined at http://yaml.org/type/timestamp.html
+func parseTimestamp(s string) (time.Time, bool) {
+	// TODO write code to check all the formats supported by
+	// http://yaml.org/type/timestamp.html instead of using time.Parse.
+
+	// Quick check: all date formats start with YYYY-.
+	i := 0
+	for ; i < len(s); i++ {
+		if c := s[i]; c < '0' || c > '9' {
+			break
+		}
+	}
+	if i != 4 || i == len(s) || s[i] != '-' {
+		return time.Time{}, false
+	}
+	for _, format := range allowedTimestampFormats {
+		if t, err := time.Parse(format, s); err == nil {
+			return t, true
+		}
+	}
+	return time.Time{}, false
+}
diff --git a/vendor/gopkg.in/yaml.v2/scannerc.go b/vendor/gopkg.in/yaml.v2/scannerc.go
new file mode 100644
index 0000000..077fd1d
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/scannerc.go
@@ -0,0 +1,2696 @@
+package yaml
+
+import (
+	"bytes"
+	"fmt"
+)
+
+// Introduction
+// ************
+//
+// The following notes assume that you are familiar with the YAML specification
+// (http://yaml.org/spec/1.2/spec.html).  We mostly follow it, although in
+// some cases we are less restrictive that it requires.
+//
+// The process of transforming a YAML stream into a sequence of events is
+// divided on two steps: Scanning and Parsing.
+//
+// The Scanner transforms the input stream into a sequence of tokens, while the
+// parser transform the sequence of tokens produced by the Scanner into a
+// sequence of parsing events.
+//
+// The Scanner is rather clever and complicated. The Parser, on the contrary,
+// is a straightforward implementation of a recursive-descendant parser (or,
+// LL(1) parser, as it is usually called).
+//
+// Actually there are two issues of Scanning that might be called "clever", the
+// rest is quite straightforward.  The issues are "block collection start" and
+// "simple keys".  Both issues are explained below in details.
+//
+// Here the Scanning step is explained and implemented.  We start with the list
+// of all the tokens produced by the Scanner together with short descriptions.
+//
+// Now, tokens:
+//
+//      STREAM-START(encoding)          # The stream start.
+//      STREAM-END                      # The stream end.
+//      VERSION-DIRECTIVE(major,minor)  # The '%YAML' directive.
+//      TAG-DIRECTIVE(handle,prefix)    # The '%TAG' directive.
+//      DOCUMENT-START                  # '---'
+//      DOCUMENT-END                    # '...'
+//      BLOCK-SEQUENCE-START            # Indentation increase denoting a block
+//      BLOCK-MAPPING-START             # sequence or a block mapping.
+//      BLOCK-END                       # Indentation decrease.
+//      FLOW-SEQUENCE-START             # '['
+//      FLOW-SEQUENCE-END               # ']'
+//      BLOCK-SEQUENCE-START            # '{'
+//      BLOCK-SEQUENCE-END              # '}'
+//      BLOCK-ENTRY                     # '-'
+//      FLOW-ENTRY                      # ','
+//      KEY                             # '?' or nothing (simple keys).
+//      VALUE                           # ':'
+//      ALIAS(anchor)                   # '*anchor'
+//      ANCHOR(anchor)                  # '&anchor'
+//      TAG(handle,suffix)              # '!handle!suffix'
+//      SCALAR(value,style)             # A scalar.
+//
+// The following two tokens are "virtual" tokens denoting the beginning and the
+// end of the stream:
+//
+//      STREAM-START(encoding)
+//      STREAM-END
+//
+// We pass the information about the input stream encoding with the
+// STREAM-START token.
+//
+// The next two tokens are responsible for tags:
+//
+//      VERSION-DIRECTIVE(major,minor)
+//      TAG-DIRECTIVE(handle,prefix)
+//
+// Example:
+//
+//      %YAML   1.1
+//      %TAG    !   !foo
+//      %TAG    !yaml!  tag:yaml.org,2002:
+//      ---
+//
+// The correspoding sequence of tokens:
+//
+//      STREAM-START(utf-8)
+//      VERSION-DIRECTIVE(1,1)
+//      TAG-DIRECTIVE("!","!foo")
+//      TAG-DIRECTIVE("!yaml","tag:yaml.org,2002:")
+//      DOCUMENT-START
+//      STREAM-END
+//
+// Note that the VERSION-DIRECTIVE and TAG-DIRECTIVE tokens occupy a whole
+// line.
+//
+// The document start and end indicators are represented by:
+//
+//      DOCUMENT-START
+//      DOCUMENT-END
+//
+// Note that if a YAML stream contains an implicit document (without '---'
+// and '...' indicators), no DOCUMENT-START and DOCUMENT-END tokens will be
+// produced.
+//
+// In the following examples, we present whole documents together with the
+// produced tokens.
+//
+//      1. An implicit document:
+//
+//          'a scalar'
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          SCALAR("a scalar",single-quoted)
+//          STREAM-END
+//
+//      2. An explicit document:
+//
+//          ---
+//          'a scalar'
+//          ...
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          DOCUMENT-START
+//          SCALAR("a scalar",single-quoted)
+//          DOCUMENT-END
+//          STREAM-END
+//
+//      3. Several documents in a stream:
+//
+//          'a scalar'
+//          ---
+//          'another scalar'
+//          ---
+//          'yet another scalar'
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          SCALAR("a scalar",single-quoted)
+//          DOCUMENT-START
+//          SCALAR("another scalar",single-quoted)
+//          DOCUMENT-START
+//          SCALAR("yet another scalar",single-quoted)
+//          STREAM-END
+//
+// We have already introduced the SCALAR token above.  The following tokens are
+// used to describe aliases, anchors, tag, and scalars:
+//
+//      ALIAS(anchor)
+//      ANCHOR(anchor)
+//      TAG(handle,suffix)
+//      SCALAR(value,style)
+//
+// The following series of examples illustrate the usage of these tokens:
+//
+//      1. A recursive sequence:
+//
+//          &A [ *A ]
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          ANCHOR("A")
+//          FLOW-SEQUENCE-START
+//          ALIAS("A")
+//          FLOW-SEQUENCE-END
+//          STREAM-END
+//
+//      2. A tagged scalar:
+//
+//          !!float "3.14"  # A good approximation.
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          TAG("!!","float")
+//          SCALAR("3.14",double-quoted)
+//          STREAM-END
+//
+//      3. Various scalar styles:
+//
+//          --- # Implicit empty plain scalars do not produce tokens.
+//          --- a plain scalar
+//          --- 'a single-quoted scalar'
+//          --- "a double-quoted scalar"
+//          --- |-
+//            a literal scalar
+//          --- >-
+//            a folded
+//            scalar
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          DOCUMENT-START
+//          DOCUMENT-START
+//          SCALAR("a plain scalar",plain)
+//          DOCUMENT-START
+//          SCALAR("a single-quoted scalar",single-quoted)
+//          DOCUMENT-START
+//          SCALAR("a double-quoted scalar",double-quoted)
+//          DOCUMENT-START
+//          SCALAR("a literal scalar",literal)
+//          DOCUMENT-START
+//          SCALAR("a folded scalar",folded)
+//          STREAM-END
+//
+// Now it's time to review collection-related tokens. We will start with
+// flow collections:
+//
+//      FLOW-SEQUENCE-START
+//      FLOW-SEQUENCE-END
+//      FLOW-MAPPING-START
+//      FLOW-MAPPING-END
+//      FLOW-ENTRY
+//      KEY
+//      VALUE
+//
+// The tokens FLOW-SEQUENCE-START, FLOW-SEQUENCE-END, FLOW-MAPPING-START, and
+// FLOW-MAPPING-END represent the indicators '[', ']', '{', and '}'
+// correspondingly.  FLOW-ENTRY represent the ',' indicator.  Finally the
+// indicators '?' and ':', which are used for denoting mapping keys and values,
+// are represented by the KEY and VALUE tokens.
+//
+// The following examples show flow collections:
+//
+//      1. A flow sequence:
+//
+//          [item 1, item 2, item 3]
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          FLOW-SEQUENCE-START
+//          SCALAR("item 1",plain)
+//          FLOW-ENTRY
+//          SCALAR("item 2",plain)
+//          FLOW-ENTRY
+//          SCALAR("item 3",plain)
+//          FLOW-SEQUENCE-END
+//          STREAM-END
+//
+//      2. A flow mapping:
+//
+//          {
+//              a simple key: a value,  # Note that the KEY token is produced.
+//              ? a complex key: another value,
+//          }
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          FLOW-MAPPING-START
+//          KEY
+//          SCALAR("a simple key",plain)
+//          VALUE
+//          SCALAR("a value",plain)
+//          FLOW-ENTRY
+//          KEY
+//          SCALAR("a complex key",plain)
+//          VALUE
+//          SCALAR("another value",plain)
+//          FLOW-ENTRY
+//          FLOW-MAPPING-END
+//          STREAM-END
+//
+// A simple key is a key which is not denoted by the '?' indicator.  Note that
+// the Scanner still produce the KEY token whenever it encounters a simple key.
+//
+// For scanning block collections, the following tokens are used (note that we
+// repeat KEY and VALUE here):
+//
+//      BLOCK-SEQUENCE-START
+//      BLOCK-MAPPING-START
+//      BLOCK-END
+//      BLOCK-ENTRY
+//      KEY
+//      VALUE
+//
+// The tokens BLOCK-SEQUENCE-START and BLOCK-MAPPING-START denote indentation
+// increase that precedes a block collection (cf. the INDENT token in Python).
+// The token BLOCK-END denote indentation decrease that ends a block collection
+// (cf. the DEDENT token in Python).  However YAML has some syntax pecularities
+// that makes detections of these tokens more complex.
+//
+// The tokens BLOCK-ENTRY, KEY, and VALUE are used to represent the indicators
+// '-', '?', and ':' correspondingly.
+//
+// The following examples show how the tokens BLOCK-SEQUENCE-START,
+// BLOCK-MAPPING-START, and BLOCK-END are emitted by the Scanner:
+//
+//      1. Block sequences:
+//
+//          - item 1
+//          - item 2
+//          -
+//            - item 3.1
+//            - item 3.2
+//          -
+//            key 1: value 1
+//            key 2: value 2
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          BLOCK-SEQUENCE-START
+//          BLOCK-ENTRY
+//          SCALAR("item 1",plain)
+//          BLOCK-ENTRY
+//          SCALAR("item 2",plain)
+//          BLOCK-ENTRY
+//          BLOCK-SEQUENCE-START
+//          BLOCK-ENTRY
+//          SCALAR("item 3.1",plain)
+//          BLOCK-ENTRY
+//          SCALAR("item 3.2",plain)
+//          BLOCK-END
+//          BLOCK-ENTRY
+//          BLOCK-MAPPING-START
+//          KEY
+//          SCALAR("key 1",plain)
+//          VALUE
+//          SCALAR("value 1",plain)
+//          KEY
+//          SCALAR("key 2",plain)
+//          VALUE
+//          SCALAR("value 2",plain)
+//          BLOCK-END
+//          BLOCK-END
+//          STREAM-END
+//
+//      2. Block mappings:
+//
+//          a simple key: a value   # The KEY token is produced here.
+//          ? a complex key
+//          : another value
+//          a mapping:
+//            key 1: value 1
+//            key 2: value 2
+//          a sequence:
+//            - item 1
+//            - item 2
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          BLOCK-MAPPING-START
+//          KEY
+//          SCALAR("a simple key",plain)
+//          VALUE
+//          SCALAR("a value",plain)
+//          KEY
+//          SCALAR("a complex key",plain)
+//          VALUE
+//          SCALAR("another value",plain)
+//          KEY
+//          SCALAR("a mapping",plain)
+//          BLOCK-MAPPING-START
+//          KEY
+//          SCALAR("key 1",plain)
+//          VALUE
+//          SCALAR("value 1",plain)
+//          KEY
+//          SCALAR("key 2",plain)
+//          VALUE
+//          SCALAR("value 2",plain)
+//          BLOCK-END
+//          KEY
+//          SCALAR("a sequence",plain)
+//          VALUE
+//          BLOCK-SEQUENCE-START
+//          BLOCK-ENTRY
+//          SCALAR("item 1",plain)
+//          BLOCK-ENTRY
+//          SCALAR("item 2",plain)
+//          BLOCK-END
+//          BLOCK-END
+//          STREAM-END
+//
+// YAML does not always require to start a new block collection from a new
+// line.  If the current line contains only '-', '?', and ':' indicators, a new
+// block collection may start at the current line.  The following examples
+// illustrate this case:
+//
+//      1. Collections in a sequence:
+//
+//          - - item 1
+//            - item 2
+//          - key 1: value 1
+//            key 2: value 2
+//          - ? complex key
+//            : complex value
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          BLOCK-SEQUENCE-START
+//          BLOCK-ENTRY
+//          BLOCK-SEQUENCE-START
+//          BLOCK-ENTRY
+//          SCALAR("item 1",plain)
+//          BLOCK-ENTRY
+//          SCALAR("item 2",plain)
+//          BLOCK-END
+//          BLOCK-ENTRY
+//          BLOCK-MAPPING-START
+//          KEY
+//          SCALAR("key 1",plain)
+//          VALUE
+//          SCALAR("value 1",plain)
+//          KEY
+//          SCALAR("key 2",plain)
+//          VALUE
+//          SCALAR("value 2",plain)
+//          BLOCK-END
+//          BLOCK-ENTRY
+//          BLOCK-MAPPING-START
+//          KEY
+//          SCALAR("complex key")
+//          VALUE
+//          SCALAR("complex value")
+//          BLOCK-END
+//          BLOCK-END
+//          STREAM-END
+//
+//      2. Collections in a mapping:
+//
+//          ? a sequence
+//          : - item 1
+//            - item 2
+//          ? a mapping
+//          : key 1: value 1
+//            key 2: value 2
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          BLOCK-MAPPING-START
+//          KEY
+//          SCALAR("a sequence",plain)
+//          VALUE
+//          BLOCK-SEQUENCE-START
+//          BLOCK-ENTRY
+//          SCALAR("item 1",plain)
+//          BLOCK-ENTRY
+//          SCALAR("item 2",plain)
+//          BLOCK-END
+//          KEY
+//          SCALAR("a mapping",plain)
+//          VALUE
+//          BLOCK-MAPPING-START
+//          KEY
+//          SCALAR("key 1",plain)
+//          VALUE
+//          SCALAR("value 1",plain)
+//          KEY
+//          SCALAR("key 2",plain)
+//          VALUE
+//          SCALAR("value 2",plain)
+//          BLOCK-END
+//          BLOCK-END
+//          STREAM-END
+//
+// YAML also permits non-indented sequences if they are included into a block
+// mapping.  In this case, the token BLOCK-SEQUENCE-START is not produced:
+//
+//      key:
+//      - item 1    # BLOCK-SEQUENCE-START is NOT produced here.
+//      - item 2
+//
+// Tokens:
+//
+//      STREAM-START(utf-8)
+//      BLOCK-MAPPING-START
+//      KEY
+//      SCALAR("key",plain)
+//      VALUE
+//      BLOCK-ENTRY
+//      SCALAR("item 1",plain)
+//      BLOCK-ENTRY
+//      SCALAR("item 2",plain)
+//      BLOCK-END
+//
+
+// Ensure that the buffer contains the required number of characters.
+// Return true on success, false on failure (reader error or memory error).
+func cache(parser *yaml_parser_t, length int) bool {
+	// [Go] This was inlined: !cache(A, B) -> unread < B && !update(A, B)
+	return parser.unread >= length || yaml_parser_update_buffer(parser, length)
+}
+
+// Advance the buffer pointer.
+func skip(parser *yaml_parser_t) {
+	parser.mark.index++
+	parser.mark.column++
+	parser.unread--
+	parser.buffer_pos += width(parser.buffer[parser.buffer_pos])
+}
+
+func skip_line(parser *yaml_parser_t) {
+	if is_crlf(parser.buffer, parser.buffer_pos) {
+		parser.mark.index += 2
+		parser.mark.column = 0
+		parser.mark.line++
+		parser.unread -= 2
+		parser.buffer_pos += 2
+	} else if is_break(parser.buffer, parser.buffer_pos) {
+		parser.mark.index++
+		parser.mark.column = 0
+		parser.mark.line++
+		parser.unread--
+		parser.buffer_pos += width(parser.buffer[parser.buffer_pos])
+	}
+}
+
+// Copy a character to a string buffer and advance pointers.
+func read(parser *yaml_parser_t, s []byte) []byte {
+	w := width(parser.buffer[parser.buffer_pos])
+	if w == 0 {
+		panic("invalid character sequence")
+	}
+	if len(s) == 0 {
+		s = make([]byte, 0, 32)
+	}
+	if w == 1 && len(s)+w <= cap(s) {
+		s = s[:len(s)+1]
+		s[len(s)-1] = parser.buffer[parser.buffer_pos]
+		parser.buffer_pos++
+	} else {
+		s = append(s, parser.buffer[parser.buffer_pos:parser.buffer_pos+w]...)
+		parser.buffer_pos += w
+	}
+	parser.mark.index++
+	parser.mark.column++
+	parser.unread--
+	return s
+}
+
+// Copy a line break character to a string buffer and advance pointers.
+func read_line(parser *yaml_parser_t, s []byte) []byte {
+	buf := parser.buffer
+	pos := parser.buffer_pos
+	switch {
+	case buf[pos] == '\r' && buf[pos+1] == '\n':
+		// CR LF . LF
+		s = append(s, '\n')
+		parser.buffer_pos += 2
+		parser.mark.index++
+		parser.unread--
+	case buf[pos] == '\r' || buf[pos] == '\n':
+		// CR|LF . LF
+		s = append(s, '\n')
+		parser.buffer_pos += 1
+	case buf[pos] == '\xC2' && buf[pos+1] == '\x85':
+		// NEL . LF
+		s = append(s, '\n')
+		parser.buffer_pos += 2
+	case buf[pos] == '\xE2' && buf[pos+1] == '\x80' && (buf[pos+2] == '\xA8' || buf[pos+2] == '\xA9'):
+		// LS|PS . LS|PS
+		s = append(s, buf[parser.buffer_pos:pos+3]...)
+		parser.buffer_pos += 3
+	default:
+		return s
+	}
+	parser.mark.index++
+	parser.mark.column = 0
+	parser.mark.line++
+	parser.unread--
+	return s
+}
+
+// Get the next token.
+func yaml_parser_scan(parser *yaml_parser_t, token *yaml_token_t) bool {
+	// Erase the token object.
+	*token = yaml_token_t{} // [Go] Is this necessary?
+
+	// No tokens after STREAM-END or error.
+	if parser.stream_end_produced || parser.error != yaml_NO_ERROR {
+		return true
+	}
+
+	// Ensure that the tokens queue contains enough tokens.
+	if !parser.token_available {
+		if !yaml_parser_fetch_more_tokens(parser) {
+			return false
+		}
+	}
+
+	// Fetch the next token from the queue.
+	*token = parser.tokens[parser.tokens_head]
+	parser.tokens_head++
+	parser.tokens_parsed++
+	parser.token_available = false
+
+	if token.typ == yaml_STREAM_END_TOKEN {
+		parser.stream_end_produced = true
+	}
+	return true
+}
+
+// Set the scanner error and return false.
+func yaml_parser_set_scanner_error(parser *yaml_parser_t, context string, context_mark yaml_mark_t, problem string) bool {
+	parser.error = yaml_SCANNER_ERROR
+	parser.context = context
+	parser.context_mark = context_mark
+	parser.problem = problem
+	parser.problem_mark = parser.mark
+	return false
+}
+
+func yaml_parser_set_scanner_tag_error(parser *yaml_parser_t, directive bool, context_mark yaml_mark_t, problem string) bool {
+	context := "while parsing a tag"
+	if directive {
+		context = "while parsing a %TAG directive"
+	}
+	return yaml_parser_set_scanner_error(parser, context, context_mark, problem)
+}
+
+func trace(args ...interface{}) func() {
+	pargs := append([]interface{}{"+++"}, args...)
+	fmt.Println(pargs...)
+	pargs = append([]interface{}{"---"}, args...)
+	return func() { fmt.Println(pargs...) }
+}
+
+// Ensure that the tokens queue contains at least one token which can be
+// returned to the Parser.
+func yaml_parser_fetch_more_tokens(parser *yaml_parser_t) bool {
+	// While we need more tokens to fetch, do it.
+	for {
+		// Check if we really need to fetch more tokens.
+		need_more_tokens := false
+
+		if parser.tokens_head == len(parser.tokens) {
+			// Queue is empty.
+			need_more_tokens = true
+		} else {
+			// Check if any potential simple key may occupy the head position.
+			if !yaml_parser_stale_simple_keys(parser) {
+				return false
+			}
+
+			for i := range parser.simple_keys {
+				simple_key := &parser.simple_keys[i]
+				if simple_key.possible && simple_key.token_number == parser.tokens_parsed {
+					need_more_tokens = true
+					break
+				}
+			}
+		}
+
+		// We are finished.
+		if !need_more_tokens {
+			break
+		}
+		// Fetch the next token.
+		if !yaml_parser_fetch_next_token(parser) {
+			return false
+		}
+	}
+
+	parser.token_available = true
+	return true
+}
+
+// The dispatcher for token fetchers.
+func yaml_parser_fetch_next_token(parser *yaml_parser_t) bool {
+	// Ensure that the buffer is initialized.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+
+	// Check if we just started scanning.  Fetch STREAM-START then.
+	if !parser.stream_start_produced {
+		return yaml_parser_fetch_stream_start(parser)
+	}
+
+	// Eat whitespaces and comments until we reach the next token.
+	if !yaml_parser_scan_to_next_token(parser) {
+		return false
+	}
+
+	// Remove obsolete potential simple keys.
+	if !yaml_parser_stale_simple_keys(parser) {
+		return false
+	}
+
+	// Check the indentation level against the current column.
+	if !yaml_parser_unroll_indent(parser, parser.mark.column) {
+		return false
+	}
+
+	// Ensure that the buffer contains at least 4 characters.  4 is the length
+	// of the longest indicators ('--- ' and '... ').
+	if parser.unread < 4 && !yaml_parser_update_buffer(parser, 4) {
+		return false
+	}
+
+	// Is it the end of the stream?
+	if is_z(parser.buffer, parser.buffer_pos) {
+		return yaml_parser_fetch_stream_end(parser)
+	}
+
+	// Is it a directive?
+	if parser.mark.column == 0 && parser.buffer[parser.buffer_pos] == '%' {
+		return yaml_parser_fetch_directive(parser)
+	}
+
+	buf := parser.buffer
+	pos := parser.buffer_pos
+
+	// Is it the document start indicator?
+	if parser.mark.column == 0 && buf[pos] == '-' && buf[pos+1] == '-' && buf[pos+2] == '-' && is_blankz(buf, pos+3) {
+		return yaml_parser_fetch_document_indicator(parser, yaml_DOCUMENT_START_TOKEN)
+	}
+
+	// Is it the document end indicator?
+	if parser.mark.column == 0 && buf[pos] == '.' && buf[pos+1] == '.' && buf[pos+2] == '.' && is_blankz(buf, pos+3) {
+		return yaml_parser_fetch_document_indicator(parser, yaml_DOCUMENT_END_TOKEN)
+	}
+
+	// Is it the flow sequence start indicator?
+	if buf[pos] == '[' {
+		return yaml_parser_fetch_flow_collection_start(parser, yaml_FLOW_SEQUENCE_START_TOKEN)
+	}
+
+	// Is it the flow mapping start indicator?
+	if parser.buffer[parser.buffer_pos] == '{' {
+		return yaml_parser_fetch_flow_collection_start(parser, yaml_FLOW_MAPPING_START_TOKEN)
+	}
+
+	// Is it the flow sequence end indicator?
+	if parser.buffer[parser.buffer_pos] == ']' {
+		return yaml_parser_fetch_flow_collection_end(parser,
+			yaml_FLOW_SEQUENCE_END_TOKEN)
+	}
+
+	// Is it the flow mapping end indicator?
+	if parser.buffer[parser.buffer_pos] == '}' {
+		return yaml_parser_fetch_flow_collection_end(parser,
+			yaml_FLOW_MAPPING_END_TOKEN)
+	}
+
+	// Is it the flow entry indicator?
+	if parser.buffer[parser.buffer_pos] == ',' {
+		return yaml_parser_fetch_flow_entry(parser)
+	}
+
+	// Is it the block entry indicator?
+	if parser.buffer[parser.buffer_pos] == '-' && is_blankz(parser.buffer, parser.buffer_pos+1) {
+		return yaml_parser_fetch_block_entry(parser)
+	}
+
+	// Is it the key indicator?
+	if parser.buffer[parser.buffer_pos] == '?' && (parser.flow_level > 0 || is_blankz(parser.buffer, parser.buffer_pos+1)) {
+		return yaml_parser_fetch_key(parser)
+	}
+
+	// Is it the value indicator?
+	if parser.buffer[parser.buffer_pos] == ':' && (parser.flow_level > 0 || is_blankz(parser.buffer, parser.buffer_pos+1)) {
+		return yaml_parser_fetch_value(parser)
+	}
+
+	// Is it an alias?
+	if parser.buffer[parser.buffer_pos] == '*' {
+		return yaml_parser_fetch_anchor(parser, yaml_ALIAS_TOKEN)
+	}
+
+	// Is it an anchor?
+	if parser.buffer[parser.buffer_pos] == '&' {
+		return yaml_parser_fetch_anchor(parser, yaml_ANCHOR_TOKEN)
+	}
+
+	// Is it a tag?
+	if parser.buffer[parser.buffer_pos] == '!' {
+		return yaml_parser_fetch_tag(parser)
+	}
+
+	// Is it a literal scalar?
+	if parser.buffer[parser.buffer_pos] == '|' && parser.flow_level == 0 {
+		return yaml_parser_fetch_block_scalar(parser, true)
+	}
+
+	// Is it a folded scalar?
+	if parser.buffer[parser.buffer_pos] == '>' && parser.flow_level == 0 {
+		return yaml_parser_fetch_block_scalar(parser, false)
+	}
+
+	// Is it a single-quoted scalar?
+	if parser.buffer[parser.buffer_pos] == '\'' {
+		return yaml_parser_fetch_flow_scalar(parser, true)
+	}
+
+	// Is it a double-quoted scalar?
+	if parser.buffer[parser.buffer_pos] == '"' {
+		return yaml_parser_fetch_flow_scalar(parser, false)
+	}
+
+	// Is it a plain scalar?
+	//
+	// A plain scalar may start with any non-blank characters except
+	//
+	//      '-', '?', ':', ',', '[', ']', '{', '}',
+	//      '#', '&', '*', '!', '|', '>', '\'', '\"',
+	//      '%', '@', '`'.
+	//
+	// In the block context (and, for the '-' indicator, in the flow context
+	// too), it may also start with the characters
+	//
+	//      '-', '?', ':'
+	//
+	// if it is followed by a non-space character.
+	//
+	// The last rule is more restrictive than the specification requires.
+	// [Go] Make this logic more reasonable.
+	//switch parser.buffer[parser.buffer_pos] {
+	//case '-', '?', ':', ',', '?', '-', ',', ':', ']', '[', '}', '{', '&', '#', '!', '*', '>', '|', '"', '\'', '@', '%', '-', '`':
+	//}
+	if !(is_blankz(parser.buffer, parser.buffer_pos) || parser.buffer[parser.buffer_pos] == '-' ||
+		parser.buffer[parser.buffer_pos] == '?' || parser.buffer[parser.buffer_pos] == ':' ||
+		parser.buffer[parser.buffer_pos] == ',' || parser.buffer[parser.buffer_pos] == '[' ||
+		parser.buffer[parser.buffer_pos] == ']' || parser.buffer[parser.buffer_pos] == '{' ||
+		parser.buffer[parser.buffer_pos] == '}' || parser.buffer[parser.buffer_pos] == '#' ||
+		parser.buffer[parser.buffer_pos] == '&' || parser.buffer[parser.buffer_pos] == '*' ||
+		parser.buffer[parser.buffer_pos] == '!' || parser.buffer[parser.buffer_pos] == '|' ||
+		parser.buffer[parser.buffer_pos] == '>' || parser.buffer[parser.buffer_pos] == '\'' ||
+		parser.buffer[parser.buffer_pos] == '"' || parser.buffer[parser.buffer_pos] == '%' ||
+		parser.buffer[parser.buffer_pos] == '@' || parser.buffer[parser.buffer_pos] == '`') ||
+		(parser.buffer[parser.buffer_pos] == '-' && !is_blank(parser.buffer, parser.buffer_pos+1)) ||
+		(parser.flow_level == 0 &&
+			(parser.buffer[parser.buffer_pos] == '?' || parser.buffer[parser.buffer_pos] == ':') &&
+			!is_blankz(parser.buffer, parser.buffer_pos+1)) {
+		return yaml_parser_fetch_plain_scalar(parser)
+	}
+
+	// If we don't determine the token type so far, it is an error.
+	return yaml_parser_set_scanner_error(parser,
+		"while scanning for the next token", parser.mark,
+		"found character that cannot start any token")
+}
+
+// Check the list of potential simple keys and remove the positions that
+// cannot contain simple keys anymore.
+func yaml_parser_stale_simple_keys(parser *yaml_parser_t) bool {
+	// Check for a potential simple key for each flow level.
+	for i := range parser.simple_keys {
+		simple_key := &parser.simple_keys[i]
+
+		// The specification requires that a simple key
+		//
+		//  - is limited to a single line,
+		//  - is shorter than 1024 characters.
+		if simple_key.possible && (simple_key.mark.line < parser.mark.line || simple_key.mark.index+1024 < parser.mark.index) {
+
+			// Check if the potential simple key to be removed is required.
+			if simple_key.required {
+				return yaml_parser_set_scanner_error(parser,
+					"while scanning a simple key", simple_key.mark,
+					"could not find expected ':'")
+			}
+			simple_key.possible = false
+		}
+	}
+	return true
+}
+
+// Check if a simple key may start at the current position and add it if
+// needed.
+func yaml_parser_save_simple_key(parser *yaml_parser_t) bool {
+	// A simple key is required at the current position if the scanner is in
+	// the block context and the current column coincides with the indentation
+	// level.
+
+	required := parser.flow_level == 0 && parser.indent == parser.mark.column
+
+	//
+	// If the current position may start a simple key, save it.
+	//
+	if parser.simple_key_allowed {
+		simple_key := yaml_simple_key_t{
+			possible:     true,
+			required:     required,
+			token_number: parser.tokens_parsed + (len(parser.tokens) - parser.tokens_head),
+		}
+		simple_key.mark = parser.mark
+
+		if !yaml_parser_remove_simple_key(parser) {
+			return false
+		}
+		parser.simple_keys[len(parser.simple_keys)-1] = simple_key
+	}
+	return true
+}
+
+// Remove a potential simple key at the current flow level.
+func yaml_parser_remove_simple_key(parser *yaml_parser_t) bool {
+	i := len(parser.simple_keys) - 1
+	if parser.simple_keys[i].possible {
+		// If the key is required, it is an error.
+		if parser.simple_keys[i].required {
+			return yaml_parser_set_scanner_error(parser,
+				"while scanning a simple key", parser.simple_keys[i].mark,
+				"could not find expected ':'")
+		}
+	}
+	// Remove the key from the stack.
+	parser.simple_keys[i].possible = false
+	return true
+}
+
+// Increase the flow level and resize the simple key list if needed.
+func yaml_parser_increase_flow_level(parser *yaml_parser_t) bool {
+	// Reset the simple key on the next level.
+	parser.simple_keys = append(parser.simple_keys, yaml_simple_key_t{})
+
+	// Increase the flow level.
+	parser.flow_level++
+	return true
+}
+
+// Decrease the flow level.
+func yaml_parser_decrease_flow_level(parser *yaml_parser_t) bool {
+	if parser.flow_level > 0 {
+		parser.flow_level--
+		parser.simple_keys = parser.simple_keys[:len(parser.simple_keys)-1]
+	}
+	return true
+}
+
+// Push the current indentation level to the stack and set the new level
+// the current column is greater than the indentation level.  In this case,
+// append or insert the specified token into the token queue.
+func yaml_parser_roll_indent(parser *yaml_parser_t, column, number int, typ yaml_token_type_t, mark yaml_mark_t) bool {
+	// In the flow context, do nothing.
+	if parser.flow_level > 0 {
+		return true
+	}
+
+	if parser.indent < column {
+		// Push the current indentation level to the stack and set the new
+		// indentation level.
+		parser.indents = append(parser.indents, parser.indent)
+		parser.indent = column
+
+		// Create a token and insert it into the queue.
+		token := yaml_token_t{
+			typ:        typ,
+			start_mark: mark,
+			end_mark:   mark,
+		}
+		if number > -1 {
+			number -= parser.tokens_parsed
+		}
+		yaml_insert_token(parser, number, &token)
+	}
+	return true
+}
+
+// Pop indentation levels from the indents stack until the current level
+// becomes less or equal to the column.  For each indentation level, append
+// the BLOCK-END token.
+func yaml_parser_unroll_indent(parser *yaml_parser_t, column int) bool {
+	// In the flow context, do nothing.
+	if parser.flow_level > 0 {
+		return true
+	}
+
+	// Loop through the indentation levels in the stack.
+	for parser.indent > column {
+		// Create a token and append it to the queue.
+		token := yaml_token_t{
+			typ:        yaml_BLOCK_END_TOKEN,
+			start_mark: parser.mark,
+			end_mark:   parser.mark,
+		}
+		yaml_insert_token(parser, -1, &token)
+
+		// Pop the indentation level.
+		parser.indent = parser.indents[len(parser.indents)-1]
+		parser.indents = parser.indents[:len(parser.indents)-1]
+	}
+	return true
+}
+
+// Initialize the scanner and produce the STREAM-START token.
+func yaml_parser_fetch_stream_start(parser *yaml_parser_t) bool {
+
+	// Set the initial indentation.
+	parser.indent = -1
+
+	// Initialize the simple key stack.
+	parser.simple_keys = append(parser.simple_keys, yaml_simple_key_t{})
+
+	// A simple key is allowed at the beginning of the stream.
+	parser.simple_key_allowed = true
+
+	// We have started.
+	parser.stream_start_produced = true
+
+	// Create the STREAM-START token and append it to the queue.
+	token := yaml_token_t{
+		typ:        yaml_STREAM_START_TOKEN,
+		start_mark: parser.mark,
+		end_mark:   parser.mark,
+		encoding:   parser.encoding,
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the STREAM-END token and shut down the scanner.
+func yaml_parser_fetch_stream_end(parser *yaml_parser_t) bool {
+
+	// Force new line.
+	if parser.mark.column != 0 {
+		parser.mark.column = 0
+		parser.mark.line++
+	}
+
+	// Reset the indentation level.
+	if !yaml_parser_unroll_indent(parser, -1) {
+		return false
+	}
+
+	// Reset simple keys.
+	if !yaml_parser_remove_simple_key(parser) {
+		return false
+	}
+
+	parser.simple_key_allowed = false
+
+	// Create the STREAM-END token and append it to the queue.
+	token := yaml_token_t{
+		typ:        yaml_STREAM_END_TOKEN,
+		start_mark: parser.mark,
+		end_mark:   parser.mark,
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce a VERSION-DIRECTIVE or TAG-DIRECTIVE token.
+func yaml_parser_fetch_directive(parser *yaml_parser_t) bool {
+	// Reset the indentation level.
+	if !yaml_parser_unroll_indent(parser, -1) {
+		return false
+	}
+
+	// Reset simple keys.
+	if !yaml_parser_remove_simple_key(parser) {
+		return false
+	}
+
+	parser.simple_key_allowed = false
+
+	// Create the YAML-DIRECTIVE or TAG-DIRECTIVE token.
+	token := yaml_token_t{}
+	if !yaml_parser_scan_directive(parser, &token) {
+		return false
+	}
+	// Append the token to the queue.
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the DOCUMENT-START or DOCUMENT-END token.
+func yaml_parser_fetch_document_indicator(parser *yaml_parser_t, typ yaml_token_type_t) bool {
+	// Reset the indentation level.
+	if !yaml_parser_unroll_indent(parser, -1) {
+		return false
+	}
+
+	// Reset simple keys.
+	if !yaml_parser_remove_simple_key(parser) {
+		return false
+	}
+
+	parser.simple_key_allowed = false
+
+	// Consume the token.
+	start_mark := parser.mark
+
+	skip(parser)
+	skip(parser)
+	skip(parser)
+
+	end_mark := parser.mark
+
+	// Create the DOCUMENT-START or DOCUMENT-END token.
+	token := yaml_token_t{
+		typ:        typ,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+	}
+	// Append the token to the queue.
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the FLOW-SEQUENCE-START or FLOW-MAPPING-START token.
+func yaml_parser_fetch_flow_collection_start(parser *yaml_parser_t, typ yaml_token_type_t) bool {
+	// The indicators '[' and '{' may start a simple key.
+	if !yaml_parser_save_simple_key(parser) {
+		return false
+	}
+
+	// Increase the flow level.
+	if !yaml_parser_increase_flow_level(parser) {
+		return false
+	}
+
+	// A simple key may follow the indicators '[' and '{'.
+	parser.simple_key_allowed = true
+
+	// Consume the token.
+	start_mark := parser.mark
+	skip(parser)
+	end_mark := parser.mark
+
+	// Create the FLOW-SEQUENCE-START of FLOW-MAPPING-START token.
+	token := yaml_token_t{
+		typ:        typ,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+	}
+	// Append the token to the queue.
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the FLOW-SEQUENCE-END or FLOW-MAPPING-END token.
+func yaml_parser_fetch_flow_collection_end(parser *yaml_parser_t, typ yaml_token_type_t) bool {
+	// Reset any potential simple key on the current flow level.
+	if !yaml_parser_remove_simple_key(parser) {
+		return false
+	}
+
+	// Decrease the flow level.
+	if !yaml_parser_decrease_flow_level(parser) {
+		return false
+	}
+
+	// No simple keys after the indicators ']' and '}'.
+	parser.simple_key_allowed = false
+
+	// Consume the token.
+
+	start_mark := parser.mark
+	skip(parser)
+	end_mark := parser.mark
+
+	// Create the FLOW-SEQUENCE-END of FLOW-MAPPING-END token.
+	token := yaml_token_t{
+		typ:        typ,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+	}
+	// Append the token to the queue.
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the FLOW-ENTRY token.
+func yaml_parser_fetch_flow_entry(parser *yaml_parser_t) bool {
+	// Reset any potential simple keys on the current flow level.
+	if !yaml_parser_remove_simple_key(parser) {
+		return false
+	}
+
+	// Simple keys are allowed after ','.
+	parser.simple_key_allowed = true
+
+	// Consume the token.
+	start_mark := parser.mark
+	skip(parser)
+	end_mark := parser.mark
+
+	// Create the FLOW-ENTRY token and append it to the queue.
+	token := yaml_token_t{
+		typ:        yaml_FLOW_ENTRY_TOKEN,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the BLOCK-ENTRY token.
+func yaml_parser_fetch_block_entry(parser *yaml_parser_t) bool {
+	// Check if the scanner is in the block context.
+	if parser.flow_level == 0 {
+		// Check if we are allowed to start a new entry.
+		if !parser.simple_key_allowed {
+			return yaml_parser_set_scanner_error(parser, "", parser.mark,
+				"block sequence entries are not allowed in this context")
+		}
+		// Add the BLOCK-SEQUENCE-START token if needed.
+		if !yaml_parser_roll_indent(parser, parser.mark.column, -1, yaml_BLOCK_SEQUENCE_START_TOKEN, parser.mark) {
+			return false
+		}
+	} else {
+		// It is an error for the '-' indicator to occur in the flow context,
+		// but we let the Parser detect and report about it because the Parser
+		// is able to point to the context.
+	}
+
+	// Reset any potential simple keys on the current flow level.
+	if !yaml_parser_remove_simple_key(parser) {
+		return false
+	}
+
+	// Simple keys are allowed after '-'.
+	parser.simple_key_allowed = true
+
+	// Consume the token.
+	start_mark := parser.mark
+	skip(parser)
+	end_mark := parser.mark
+
+	// Create the BLOCK-ENTRY token and append it to the queue.
+	token := yaml_token_t{
+		typ:        yaml_BLOCK_ENTRY_TOKEN,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the KEY token.
+func yaml_parser_fetch_key(parser *yaml_parser_t) bool {
+
+	// In the block context, additional checks are required.
+	if parser.flow_level == 0 {
+		// Check if we are allowed to start a new key (not nessesary simple).
+		if !parser.simple_key_allowed {
+			return yaml_parser_set_scanner_error(parser, "", parser.mark,
+				"mapping keys are not allowed in this context")
+		}
+		// Add the BLOCK-MAPPING-START token if needed.
+		if !yaml_parser_roll_indent(parser, parser.mark.column, -1, yaml_BLOCK_MAPPING_START_TOKEN, parser.mark) {
+			return false
+		}
+	}
+
+	// Reset any potential simple keys on the current flow level.
+	if !yaml_parser_remove_simple_key(parser) {
+		return false
+	}
+
+	// Simple keys are allowed after '?' in the block context.
+	parser.simple_key_allowed = parser.flow_level == 0
+
+	// Consume the token.
+	start_mark := parser.mark
+	skip(parser)
+	end_mark := parser.mark
+
+	// Create the KEY token and append it to the queue.
+	token := yaml_token_t{
+		typ:        yaml_KEY_TOKEN,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the VALUE token.
+func yaml_parser_fetch_value(parser *yaml_parser_t) bool {
+
+	simple_key := &parser.simple_keys[len(parser.simple_keys)-1]
+
+	// Have we found a simple key?
+	if simple_key.possible {
+		// Create the KEY token and insert it into the queue.
+		token := yaml_token_t{
+			typ:        yaml_KEY_TOKEN,
+			start_mark: simple_key.mark,
+			end_mark:   simple_key.mark,
+		}
+		yaml_insert_token(parser, simple_key.token_number-parser.tokens_parsed, &token)
+
+		// In the block context, we may need to add the BLOCK-MAPPING-START token.
+		if !yaml_parser_roll_indent(parser, simple_key.mark.column,
+			simple_key.token_number,
+			yaml_BLOCK_MAPPING_START_TOKEN, simple_key.mark) {
+			return false
+		}
+
+		// Remove the simple key.
+		simple_key.possible = false
+
+		// A simple key cannot follow another simple key.
+		parser.simple_key_allowed = false
+
+	} else {
+		// The ':' indicator follows a complex key.
+
+		// In the block context, extra checks are required.
+		if parser.flow_level == 0 {
+
+			// Check if we are allowed to start a complex value.
+			if !parser.simple_key_allowed {
+				return yaml_parser_set_scanner_error(parser, "", parser.mark,
+					"mapping values are not allowed in this context")
+			}
+
+			// Add the BLOCK-MAPPING-START token if needed.
+			if !yaml_parser_roll_indent(parser, parser.mark.column, -1, yaml_BLOCK_MAPPING_START_TOKEN, parser.mark) {
+				return false
+			}
+		}
+
+		// Simple keys after ':' are allowed in the block context.
+		parser.simple_key_allowed = parser.flow_level == 0
+	}
+
+	// Consume the token.
+	start_mark := parser.mark
+	skip(parser)
+	end_mark := parser.mark
+
+	// Create the VALUE token and append it to the queue.
+	token := yaml_token_t{
+		typ:        yaml_VALUE_TOKEN,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the ALIAS or ANCHOR token.
+func yaml_parser_fetch_anchor(parser *yaml_parser_t, typ yaml_token_type_t) bool {
+	// An anchor or an alias could be a simple key.
+	if !yaml_parser_save_simple_key(parser) {
+		return false
+	}
+
+	// A simple key cannot follow an anchor or an alias.
+	parser.simple_key_allowed = false
+
+	// Create the ALIAS or ANCHOR token and append it to the queue.
+	var token yaml_token_t
+	if !yaml_parser_scan_anchor(parser, &token, typ) {
+		return false
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the TAG token.
+func yaml_parser_fetch_tag(parser *yaml_parser_t) bool {
+	// A tag could be a simple key.
+	if !yaml_parser_save_simple_key(parser) {
+		return false
+	}
+
+	// A simple key cannot follow a tag.
+	parser.simple_key_allowed = false
+
+	// Create the TAG token and append it to the queue.
+	var token yaml_token_t
+	if !yaml_parser_scan_tag(parser, &token) {
+		return false
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the SCALAR(...,literal) or SCALAR(...,folded) tokens.
+func yaml_parser_fetch_block_scalar(parser *yaml_parser_t, literal bool) bool {
+	// Remove any potential simple keys.
+	if !yaml_parser_remove_simple_key(parser) {
+		return false
+	}
+
+	// A simple key may follow a block scalar.
+	parser.simple_key_allowed = true
+
+	// Create the SCALAR token and append it to the queue.
+	var token yaml_token_t
+	if !yaml_parser_scan_block_scalar(parser, &token, literal) {
+		return false
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the SCALAR(...,single-quoted) or SCALAR(...,double-quoted) tokens.
+func yaml_parser_fetch_flow_scalar(parser *yaml_parser_t, single bool) bool {
+	// A plain scalar could be a simple key.
+	if !yaml_parser_save_simple_key(parser) {
+		return false
+	}
+
+	// A simple key cannot follow a flow scalar.
+	parser.simple_key_allowed = false
+
+	// Create the SCALAR token and append it to the queue.
+	var token yaml_token_t
+	if !yaml_parser_scan_flow_scalar(parser, &token, single) {
+		return false
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the SCALAR(...,plain) token.
+func yaml_parser_fetch_plain_scalar(parser *yaml_parser_t) bool {
+	// A plain scalar could be a simple key.
+	if !yaml_parser_save_simple_key(parser) {
+		return false
+	}
+
+	// A simple key cannot follow a flow scalar.
+	parser.simple_key_allowed = false
+
+	// Create the SCALAR token and append it to the queue.
+	var token yaml_token_t
+	if !yaml_parser_scan_plain_scalar(parser, &token) {
+		return false
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Eat whitespaces and comments until the next token is found.
+func yaml_parser_scan_to_next_token(parser *yaml_parser_t) bool {
+
+	// Until the next token is not found.
+	for {
+		// Allow the BOM mark to start a line.
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+		if parser.mark.column == 0 && is_bom(parser.buffer, parser.buffer_pos) {
+			skip(parser)
+		}
+
+		// Eat whitespaces.
+		// Tabs are allowed:
+		//  - in the flow context
+		//  - in the block context, but not at the beginning of the line or
+		//  after '-', '?', or ':' (complex value).
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+
+		for parser.buffer[parser.buffer_pos] == ' ' || ((parser.flow_level > 0 || !parser.simple_key_allowed) && parser.buffer[parser.buffer_pos] == '\t') {
+			skip(parser)
+			if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+				return false
+			}
+		}
+
+		// Eat a comment until a line break.
+		if parser.buffer[parser.buffer_pos] == '#' {
+			for !is_breakz(parser.buffer, parser.buffer_pos) {
+				skip(parser)
+				if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+					return false
+				}
+			}
+		}
+
+		// If it is a line break, eat it.
+		if is_break(parser.buffer, parser.buffer_pos) {
+			if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+				return false
+			}
+			skip_line(parser)
+
+			// In the block context, a new line may start a simple key.
+			if parser.flow_level == 0 {
+				parser.simple_key_allowed = true
+			}
+		} else {
+			break // We have found a token.
+		}
+	}
+
+	return true
+}
+
+// Scan a YAML-DIRECTIVE or TAG-DIRECTIVE token.
+//
+// Scope:
+//      %YAML    1.1    # a comment \n
+//      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+//      %TAG    !yaml!  tag:yaml.org,2002:  \n
+//      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+//
+func yaml_parser_scan_directive(parser *yaml_parser_t, token *yaml_token_t) bool {
+	// Eat '%'.
+	start_mark := parser.mark
+	skip(parser)
+
+	// Scan the directive name.
+	var name []byte
+	if !yaml_parser_scan_directive_name(parser, start_mark, &name) {
+		return false
+	}
+
+	// Is it a YAML directive?
+	if bytes.Equal(name, []byte("YAML")) {
+		// Scan the VERSION directive value.
+		var major, minor int8
+		if !yaml_parser_scan_version_directive_value(parser, start_mark, &major, &minor) {
+			return false
+		}
+		end_mark := parser.mark
+
+		// Create a VERSION-DIRECTIVE token.
+		*token = yaml_token_t{
+			typ:        yaml_VERSION_DIRECTIVE_TOKEN,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			major:      major,
+			minor:      minor,
+		}
+
+		// Is it a TAG directive?
+	} else if bytes.Equal(name, []byte("TAG")) {
+		// Scan the TAG directive value.
+		var handle, prefix []byte
+		if !yaml_parser_scan_tag_directive_value(parser, start_mark, &handle, &prefix) {
+			return false
+		}
+		end_mark := parser.mark
+
+		// Create a TAG-DIRECTIVE token.
+		*token = yaml_token_t{
+			typ:        yaml_TAG_DIRECTIVE_TOKEN,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			value:      handle,
+			prefix:     prefix,
+		}
+
+		// Unknown directive.
+	} else {
+		yaml_parser_set_scanner_error(parser, "while scanning a directive",
+			start_mark, "found unknown directive name")
+		return false
+	}
+
+	// Eat the rest of the line including any comments.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+
+	for is_blank(parser.buffer, parser.buffer_pos) {
+		skip(parser)
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+	}
+
+	if parser.buffer[parser.buffer_pos] == '#' {
+		for !is_breakz(parser.buffer, parser.buffer_pos) {
+			skip(parser)
+			if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+				return false
+			}
+		}
+	}
+
+	// Check if we are at the end of the line.
+	if !is_breakz(parser.buffer, parser.buffer_pos) {
+		yaml_parser_set_scanner_error(parser, "while scanning a directive",
+			start_mark, "did not find expected comment or line break")
+		return false
+	}
+
+	// Eat a line break.
+	if is_break(parser.buffer, parser.buffer_pos) {
+		if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+			return false
+		}
+		skip_line(parser)
+	}
+
+	return true
+}
+
+// Scan the directive name.
+//
+// Scope:
+//      %YAML   1.1     # a comment \n
+//       ^^^^
+//      %TAG    !yaml!  tag:yaml.org,2002:  \n
+//       ^^^
+//
+func yaml_parser_scan_directive_name(parser *yaml_parser_t, start_mark yaml_mark_t, name *[]byte) bool {
+	// Consume the directive name.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+
+	var s []byte
+	for is_alpha(parser.buffer, parser.buffer_pos) {
+		s = read(parser, s)
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+	}
+
+	// Check if the name is empty.
+	if len(s) == 0 {
+		yaml_parser_set_scanner_error(parser, "while scanning a directive",
+			start_mark, "could not find expected directive name")
+		return false
+	}
+
+	// Check for an blank character after the name.
+	if !is_blankz(parser.buffer, parser.buffer_pos) {
+		yaml_parser_set_scanner_error(parser, "while scanning a directive",
+			start_mark, "found unexpected non-alphabetical character")
+		return false
+	}
+	*name = s
+	return true
+}
+
+// Scan the value of VERSION-DIRECTIVE.
+//
+// Scope:
+//      %YAML   1.1     # a comment \n
+//           ^^^^^^
+func yaml_parser_scan_version_directive_value(parser *yaml_parser_t, start_mark yaml_mark_t, major, minor *int8) bool {
+	// Eat whitespaces.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+	for is_blank(parser.buffer, parser.buffer_pos) {
+		skip(parser)
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+	}
+
+	// Consume the major version number.
+	if !yaml_parser_scan_version_directive_number(parser, start_mark, major) {
+		return false
+	}
+
+	// Eat '.'.
+	if parser.buffer[parser.buffer_pos] != '.' {
+		return yaml_parser_set_scanner_error(parser, "while scanning a %YAML directive",
+			start_mark, "did not find expected digit or '.' character")
+	}
+
+	skip(parser)
+
+	// Consume the minor version number.
+	if !yaml_parser_scan_version_directive_number(parser, start_mark, minor) {
+		return false
+	}
+	return true
+}
+
+const max_number_length = 2
+
+// Scan the version number of VERSION-DIRECTIVE.
+//
+// Scope:
+//      %YAML   1.1     # a comment \n
+//              ^
+//      %YAML   1.1     # a comment \n
+//                ^
+func yaml_parser_scan_version_directive_number(parser *yaml_parser_t, start_mark yaml_mark_t, number *int8) bool {
+
+	// Repeat while the next character is digit.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+	var value, length int8
+	for is_digit(parser.buffer, parser.buffer_pos) {
+		// Check if the number is too long.
+		length++
+		if length > max_number_length {
+			return yaml_parser_set_scanner_error(parser, "while scanning a %YAML directive",
+				start_mark, "found extremely long version number")
+		}
+		value = value*10 + int8(as_digit(parser.buffer, parser.buffer_pos))
+		skip(parser)
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+	}
+
+	// Check if the number was present.
+	if length == 0 {
+		return yaml_parser_set_scanner_error(parser, "while scanning a %YAML directive",
+			start_mark, "did not find expected version number")
+	}
+	*number = value
+	return true
+}
+
+// Scan the value of a TAG-DIRECTIVE token.
+//
+// Scope:
+//      %TAG    !yaml!  tag:yaml.org,2002:  \n
+//          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+//
+func yaml_parser_scan_tag_directive_value(parser *yaml_parser_t, start_mark yaml_mark_t, handle, prefix *[]byte) bool {
+	var handle_value, prefix_value []byte
+
+	// Eat whitespaces.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+
+	for is_blank(parser.buffer, parser.buffer_pos) {
+		skip(parser)
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+	}
+
+	// Scan a handle.
+	if !yaml_parser_scan_tag_handle(parser, true, start_mark, &handle_value) {
+		return false
+	}
+
+	// Expect a whitespace.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+	if !is_blank(parser.buffer, parser.buffer_pos) {
+		yaml_parser_set_scanner_error(parser, "while scanning a %TAG directive",
+			start_mark, "did not find expected whitespace")
+		return false
+	}
+
+	// Eat whitespaces.
+	for is_blank(parser.buffer, parser.buffer_pos) {
+		skip(parser)
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+	}
+
+	// Scan a prefix.
+	if !yaml_parser_scan_tag_uri(parser, true, nil, start_mark, &prefix_value) {
+		return false
+	}
+
+	// Expect a whitespace or line break.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+	if !is_blankz(parser.buffer, parser.buffer_pos) {
+		yaml_parser_set_scanner_error(parser, "while scanning a %TAG directive",
+			start_mark, "did not find expected whitespace or line break")
+		return false
+	}
+
+	*handle = handle_value
+	*prefix = prefix_value
+	return true
+}
+
+func yaml_parser_scan_anchor(parser *yaml_parser_t, token *yaml_token_t, typ yaml_token_type_t) bool {
+	var s []byte
+
+	// Eat the indicator character.
+	start_mark := parser.mark
+	skip(parser)
+
+	// Consume the value.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+
+	for is_alpha(parser.buffer, parser.buffer_pos) {
+		s = read(parser, s)
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+	}
+
+	end_mark := parser.mark
+
+	/*
+	 * Check if length of the anchor is greater than 0 and it is followed by
+	 * a whitespace character or one of the indicators:
+	 *
+	 *      '?', ':', ',', ']', '}', '%', '@', '`'.
+	 */
+
+	if len(s) == 0 ||
+		!(is_blankz(parser.buffer, parser.buffer_pos) || parser.buffer[parser.buffer_pos] == '?' ||
+			parser.buffer[parser.buffer_pos] == ':' || parser.buffer[parser.buffer_pos] == ',' ||
+			parser.buffer[parser.buffer_pos] == ']' || parser.buffer[parser.buffer_pos] == '}' ||
+			parser.buffer[parser.buffer_pos] == '%' || parser.buffer[parser.buffer_pos] == '@' ||
+			parser.buffer[parser.buffer_pos] == '`') {
+		context := "while scanning an alias"
+		if typ == yaml_ANCHOR_TOKEN {
+			context = "while scanning an anchor"
+		}
+		yaml_parser_set_scanner_error(parser, context, start_mark,
+			"did not find expected alphabetic or numeric character")
+		return false
+	}
+
+	// Create a token.
+	*token = yaml_token_t{
+		typ:        typ,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+		value:      s,
+	}
+
+	return true
+}
+
+/*
+ * Scan a TAG token.
+ */
+
+func yaml_parser_scan_tag(parser *yaml_parser_t, token *yaml_token_t) bool {
+	var handle, suffix []byte
+
+	start_mark := parser.mark
+
+	// Check if the tag is in the canonical form.
+	if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+		return false
+	}
+
+	if parser.buffer[parser.buffer_pos+1] == '<' {
+		// Keep the handle as ''
+
+		// Eat '!<'
+		skip(parser)
+		skip(parser)
+
+		// Consume the tag value.
+		if !yaml_parser_scan_tag_uri(parser, false, nil, start_mark, &suffix) {
+			return false
+		}
+
+		// Check for '>' and eat it.
+		if parser.buffer[parser.buffer_pos] != '>' {
+			yaml_parser_set_scanner_error(parser, "while scanning a tag",
+				start_mark, "did not find the expected '>'")
+			return false
+		}
+
+		skip(parser)
+	} else {
+		// The tag has either the '!suffix' or the '!handle!suffix' form.
+
+		// First, try to scan a handle.
+		if !yaml_parser_scan_tag_handle(parser, false, start_mark, &handle) {
+			return false
+		}
+
+		// Check if it is, indeed, handle.
+		if handle[0] == '!' && len(handle) > 1 && handle[len(handle)-1] == '!' {
+			// Scan the suffix now.
+			if !yaml_parser_scan_tag_uri(parser, false, nil, start_mark, &suffix) {
+				return false
+			}
+		} else {
+			// It wasn't a handle after all.  Scan the rest of the tag.
+			if !yaml_parser_scan_tag_uri(parser, false, handle, start_mark, &suffix) {
+				return false
+			}
+
+			// Set the handle to '!'.
+			handle = []byte{'!'}
+
+			// A special case: the '!' tag.  Set the handle to '' and the
+			// suffix to '!'.
+			if len(suffix) == 0 {
+				handle, suffix = suffix, handle
+			}
+		}
+	}
+
+	// Check the character which ends the tag.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+	if !is_blankz(parser.buffer, parser.buffer_pos) {
+		yaml_parser_set_scanner_error(parser, "while scanning a tag",
+			start_mark, "did not find expected whitespace or line break")
+		return false
+	}
+
+	end_mark := parser.mark
+
+	// Create a token.
+	*token = yaml_token_t{
+		typ:        yaml_TAG_TOKEN,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+		value:      handle,
+		suffix:     suffix,
+	}
+	return true
+}
+
+// Scan a tag handle.
+func yaml_parser_scan_tag_handle(parser *yaml_parser_t, directive bool, start_mark yaml_mark_t, handle *[]byte) bool {
+	// Check the initial '!' character.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+	if parser.buffer[parser.buffer_pos] != '!' {
+		yaml_parser_set_scanner_tag_error(parser, directive,
+			start_mark, "did not find expected '!'")
+		return false
+	}
+
+	var s []byte
+
+	// Copy the '!' character.
+	s = read(parser, s)
+
+	// Copy all subsequent alphabetical and numerical characters.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+	for is_alpha(parser.buffer, parser.buffer_pos) {
+		s = read(parser, s)
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+	}
+
+	// Check if the trailing character is '!' and copy it.
+	if parser.buffer[parser.buffer_pos] == '!' {
+		s = read(parser, s)
+	} else {
+		// It's either the '!' tag or not really a tag handle.  If it's a %TAG
+		// directive, it's an error.  If it's a tag token, it must be a part of URI.
+		if directive && string(s) != "!" {
+			yaml_parser_set_scanner_tag_error(parser, directive,
+				start_mark, "did not find expected '!'")
+			return false
+		}
+	}
+
+	*handle = s
+	return true
+}
+
+// Scan a tag.
+func yaml_parser_scan_tag_uri(parser *yaml_parser_t, directive bool, head []byte, start_mark yaml_mark_t, uri *[]byte) bool {
+	//size_t length = head ? strlen((char *)head) : 0
+	var s []byte
+	hasTag := len(head) > 0
+
+	// Copy the head if needed.
+	//
+	// Note that we don't copy the leading '!' character.
+	if len(head) > 1 {
+		s = append(s, head[1:]...)
+	}
+
+	// Scan the tag.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+
+	// The set of characters that may appear in URI is as follows:
+	//
+	//      '0'-'9', 'A'-'Z', 'a'-'z', '_', '-', ';', '/', '?', ':', '@', '&',
+	//      '=', '+', '$', ',', '.', '!', '~', '*', '\'', '(', ')', '[', ']',
+	//      '%'.
+	// [Go] Convert this into more reasonable logic.
+	for is_alpha(parser.buffer, parser.buffer_pos) || parser.buffer[parser.buffer_pos] == ';' ||
+		parser.buffer[parser.buffer_pos] == '/' || parser.buffer[parser.buffer_pos] == '?' ||
+		parser.buffer[parser.buffer_pos] == ':' || parser.buffer[parser.buffer_pos] == '@' ||
+		parser.buffer[parser.buffer_pos] == '&' || parser.buffer[parser.buffer_pos] == '=' ||
+		parser.buffer[parser.buffer_pos] == '+' || parser.buffer[parser.buffer_pos] == '$' ||
+		parser.buffer[parser.buffer_pos] == ',' || parser.buffer[parser.buffer_pos] == '.' ||
+		parser.buffer[parser.buffer_pos] == '!' || parser.buffer[parser.buffer_pos] == '~' ||
+		parser.buffer[parser.buffer_pos] == '*' || parser.buffer[parser.buffer_pos] == '\'' ||
+		parser.buffer[parser.buffer_pos] == '(' || parser.buffer[parser.buffer_pos] == ')' ||
+		parser.buffer[parser.buffer_pos] == '[' || parser.buffer[parser.buffer_pos] == ']' ||
+		parser.buffer[parser.buffer_pos] == '%' {
+		// Check if it is a URI-escape sequence.
+		if parser.buffer[parser.buffer_pos] == '%' {
+			if !yaml_parser_scan_uri_escapes(parser, directive, start_mark, &s) {
+				return false
+			}
+		} else {
+			s = read(parser, s)
+		}
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+		hasTag = true
+	}
+
+	if !hasTag {
+		yaml_parser_set_scanner_tag_error(parser, directive,
+			start_mark, "did not find expected tag URI")
+		return false
+	}
+	*uri = s
+	return true
+}
+
+// Decode an URI-escape sequence corresponding to a single UTF-8 character.
+func yaml_parser_scan_uri_escapes(parser *yaml_parser_t, directive bool, start_mark yaml_mark_t, s *[]byte) bool {
+
+	// Decode the required number of characters.
+	w := 1024
+	for w > 0 {
+		// Check for a URI-escaped octet.
+		if parser.unread < 3 && !yaml_parser_update_buffer(parser, 3) {
+			return false
+		}
+
+		if !(parser.buffer[parser.buffer_pos] == '%' &&
+			is_hex(parser.buffer, parser.buffer_pos+1) &&
+			is_hex(parser.buffer, parser.buffer_pos+2)) {
+			return yaml_parser_set_scanner_tag_error(parser, directive,
+				start_mark, "did not find URI escaped octet")
+		}
+
+		// Get the octet.
+		octet := byte((as_hex(parser.buffer, parser.buffer_pos+1) << 4) + as_hex(parser.buffer, parser.buffer_pos+2))
+
+		// If it is the leading octet, determine the length of the UTF-8 sequence.
+		if w == 1024 {
+			w = width(octet)
+			if w == 0 {
+				return yaml_parser_set_scanner_tag_error(parser, directive,
+					start_mark, "found an incorrect leading UTF-8 octet")
+			}
+		} else {
+			// Check if the trailing octet is correct.
+			if octet&0xC0 != 0x80 {
+				return yaml_parser_set_scanner_tag_error(parser, directive,
+					start_mark, "found an incorrect trailing UTF-8 octet")
+			}
+		}
+
+		// Copy the octet and move the pointers.
+		*s = append(*s, octet)
+		skip(parser)
+		skip(parser)
+		skip(parser)
+		w--
+	}
+	return true
+}
+
+// Scan a block scalar.
+func yaml_parser_scan_block_scalar(parser *yaml_parser_t, token *yaml_token_t, literal bool) bool {
+	// Eat the indicator '|' or '>'.
+	start_mark := parser.mark
+	skip(parser)
+
+	// Scan the additional block scalar indicators.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+
+	// Check for a chomping indicator.
+	var chomping, increment int
+	if parser.buffer[parser.buffer_pos] == '+' || parser.buffer[parser.buffer_pos] == '-' {
+		// Set the chomping method and eat the indicator.
+		if parser.buffer[parser.buffer_pos] == '+' {
+			chomping = +1
+		} else {
+			chomping = -1
+		}
+		skip(parser)
+
+		// Check for an indentation indicator.
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+		if is_digit(parser.buffer, parser.buffer_pos) {
+			// Check that the indentation is greater than 0.
+			if parser.buffer[parser.buffer_pos] == '0' {
+				yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
+					start_mark, "found an indentation indicator equal to 0")
+				return false
+			}
+
+			// Get the indentation level and eat the indicator.
+			increment = as_digit(parser.buffer, parser.buffer_pos)
+			skip(parser)
+		}
+
+	} else if is_digit(parser.buffer, parser.buffer_pos) {
+		// Do the same as above, but in the opposite order.
+
+		if parser.buffer[parser.buffer_pos] == '0' {
+			yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
+				start_mark, "found an indentation indicator equal to 0")
+			return false
+		}
+		increment = as_digit(parser.buffer, parser.buffer_pos)
+		skip(parser)
+
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+		if parser.buffer[parser.buffer_pos] == '+' || parser.buffer[parser.buffer_pos] == '-' {
+			if parser.buffer[parser.buffer_pos] == '+' {
+				chomping = +1
+			} else {
+				chomping = -1
+			}
+			skip(parser)
+		}
+	}
+
+	// Eat whitespaces and comments to the end of the line.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+	for is_blank(parser.buffer, parser.buffer_pos) {
+		skip(parser)
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+	}
+	if parser.buffer[parser.buffer_pos] == '#' {
+		for !is_breakz(parser.buffer, parser.buffer_pos) {
+			skip(parser)
+			if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+				return false
+			}
+		}
+	}
+
+	// Check if we are at the end of the line.
+	if !is_breakz(parser.buffer, parser.buffer_pos) {
+		yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
+			start_mark, "did not find expected comment or line break")
+		return false
+	}
+
+	// Eat a line break.
+	if is_break(parser.buffer, parser.buffer_pos) {
+		if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+			return false
+		}
+		skip_line(parser)
+	}
+
+	end_mark := parser.mark
+
+	// Set the indentation level if it was specified.
+	var indent int
+	if increment > 0 {
+		if parser.indent >= 0 {
+			indent = parser.indent + increment
+		} else {
+			indent = increment
+		}
+	}
+
+	// Scan the leading line breaks and determine the indentation level if needed.
+	var s, leading_break, trailing_breaks []byte
+	if !yaml_parser_scan_block_scalar_breaks(parser, &indent, &trailing_breaks, start_mark, &end_mark) {
+		return false
+	}
+
+	// Scan the block scalar content.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+	var leading_blank, trailing_blank bool
+	for parser.mark.column == indent && !is_z(parser.buffer, parser.buffer_pos) {
+		// We are at the beginning of a non-empty line.
+
+		// Is it a trailing whitespace?
+		trailing_blank = is_blank(parser.buffer, parser.buffer_pos)
+
+		// Check if we need to fold the leading line break.
+		if !literal && !leading_blank && !trailing_blank && len(leading_break) > 0 && leading_break[0] == '\n' {
+			// Do we need to join the lines by space?
+			if len(trailing_breaks) == 0 {
+				s = append(s, ' ')
+			}
+		} else {
+			s = append(s, leading_break...)
+		}
+		leading_break = leading_break[:0]
+
+		// Append the remaining line breaks.
+		s = append(s, trailing_breaks...)
+		trailing_breaks = trailing_breaks[:0]
+
+		// Is it a leading whitespace?
+		leading_blank = is_blank(parser.buffer, parser.buffer_pos)
+
+		// Consume the current line.
+		for !is_breakz(parser.buffer, parser.buffer_pos) {
+			s = read(parser, s)
+			if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+				return false
+			}
+		}
+
+		// Consume the line break.
+		if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+			return false
+		}
+
+		leading_break = read_line(parser, leading_break)
+
+		// Eat the following indentation spaces and line breaks.
+		if !yaml_parser_scan_block_scalar_breaks(parser, &indent, &trailing_breaks, start_mark, &end_mark) {
+			return false
+		}
+	}
+
+	// Chomp the tail.
+	if chomping != -1 {
+		s = append(s, leading_break...)
+	}
+	if chomping == 1 {
+		s = append(s, trailing_breaks...)
+	}
+
+	// Create a token.
+	*token = yaml_token_t{
+		typ:        yaml_SCALAR_TOKEN,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+		value:      s,
+		style:      yaml_LITERAL_SCALAR_STYLE,
+	}
+	if !literal {
+		token.style = yaml_FOLDED_SCALAR_STYLE
+	}
+	return true
+}
+
+// Scan indentation spaces and line breaks for a block scalar.  Determine the
+// indentation level if needed.
+func yaml_parser_scan_block_scalar_breaks(parser *yaml_parser_t, indent *int, breaks *[]byte, start_mark yaml_mark_t, end_mark *yaml_mark_t) bool {
+	*end_mark = parser.mark
+
+	// Eat the indentation spaces and line breaks.
+	max_indent := 0
+	for {
+		// Eat the indentation spaces.
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+		for (*indent == 0 || parser.mark.column < *indent) && is_space(parser.buffer, parser.buffer_pos) {
+			skip(parser)
+			if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+				return false
+			}
+		}
+		if parser.mark.column > max_indent {
+			max_indent = parser.mark.column
+		}
+
+		// Check for a tab character messing the indentation.
+		if (*indent == 0 || parser.mark.column < *indent) && is_tab(parser.buffer, parser.buffer_pos) {
+			return yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
+				start_mark, "found a tab character where an indentation space is expected")
+		}
+
+		// Have we found a non-empty line?
+		if !is_break(parser.buffer, parser.buffer_pos) {
+			break
+		}
+
+		// Consume the line break.
+		if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+			return false
+		}
+		// [Go] Should really be returning breaks instead.
+		*breaks = read_line(parser, *breaks)
+		*end_mark = parser.mark
+	}
+
+	// Determine the indentation level if needed.
+	if *indent == 0 {
+		*indent = max_indent
+		if *indent < parser.indent+1 {
+			*indent = parser.indent + 1
+		}
+		if *indent < 1 {
+			*indent = 1
+		}
+	}
+	return true
+}
+
+// Scan a quoted scalar.
+func yaml_parser_scan_flow_scalar(parser *yaml_parser_t, token *yaml_token_t, single bool) bool {
+	// Eat the left quote.
+	start_mark := parser.mark
+	skip(parser)
+
+	// Consume the content of the quoted scalar.
+	var s, leading_break, trailing_breaks, whitespaces []byte
+	for {
+		// Check that there are no document indicators at the beginning of the line.
+		if parser.unread < 4 && !yaml_parser_update_buffer(parser, 4) {
+			return false
+		}
+
+		if parser.mark.column == 0 &&
+			((parser.buffer[parser.buffer_pos+0] == '-' &&
+				parser.buffer[parser.buffer_pos+1] == '-' &&
+				parser.buffer[parser.buffer_pos+2] == '-') ||
+				(parser.buffer[parser.buffer_pos+0] == '.' &&
+					parser.buffer[parser.buffer_pos+1] == '.' &&
+					parser.buffer[parser.buffer_pos+2] == '.')) &&
+			is_blankz(parser.buffer, parser.buffer_pos+3) {
+			yaml_parser_set_scanner_error(parser, "while scanning a quoted scalar",
+				start_mark, "found unexpected document indicator")
+			return false
+		}
+
+		// Check for EOF.
+		if is_z(parser.buffer, parser.buffer_pos) {
+			yaml_parser_set_scanner_error(parser, "while scanning a quoted scalar",
+				start_mark, "found unexpected end of stream")
+			return false
+		}
+
+		// Consume non-blank characters.
+		leading_blanks := false
+		for !is_blankz(parser.buffer, parser.buffer_pos) {
+			if single && parser.buffer[parser.buffer_pos] == '\'' && parser.buffer[parser.buffer_pos+1] == '\'' {
+				// Is is an escaped single quote.
+				s = append(s, '\'')
+				skip(parser)
+				skip(parser)
+
+			} else if single && parser.buffer[parser.buffer_pos] == '\'' {
+				// It is a right single quote.
+				break
+			} else if !single && parser.buffer[parser.buffer_pos] == '"' {
+				// It is a right double quote.
+				break
+
+			} else if !single && parser.buffer[parser.buffer_pos] == '\\' && is_break(parser.buffer, parser.buffer_pos+1) {
+				// It is an escaped line break.
+				if parser.unread < 3 && !yaml_parser_update_buffer(parser, 3) {
+					return false
+				}
+				skip(parser)
+				skip_line(parser)
+				leading_blanks = true
+				break
+
+			} else if !single && parser.buffer[parser.buffer_pos] == '\\' {
+				// It is an escape sequence.
+				code_length := 0
+
+				// Check the escape character.
+				switch parser.buffer[parser.buffer_pos+1] {
+				case '0':
+					s = append(s, 0)
+				case 'a':
+					s = append(s, '\x07')
+				case 'b':
+					s = append(s, '\x08')
+				case 't', '\t':
+					s = append(s, '\x09')
+				case 'n':
+					s = append(s, '\x0A')
+				case 'v':
+					s = append(s, '\x0B')
+				case 'f':
+					s = append(s, '\x0C')
+				case 'r':
+					s = append(s, '\x0D')
+				case 'e':
+					s = append(s, '\x1B')
+				case ' ':
+					s = append(s, '\x20')
+				case '"':
+					s = append(s, '"')
+				case '\'':
+					s = append(s, '\'')
+				case '\\':
+					s = append(s, '\\')
+				case 'N': // NEL (#x85)
+					s = append(s, '\xC2')
+					s = append(s, '\x85')
+				case '_': // #xA0
+					s = append(s, '\xC2')
+					s = append(s, '\xA0')
+				case 'L': // LS (#x2028)
+					s = append(s, '\xE2')
+					s = append(s, '\x80')
+					s = append(s, '\xA8')
+				case 'P': // PS (#x2029)
+					s = append(s, '\xE2')
+					s = append(s, '\x80')
+					s = append(s, '\xA9')
+				case 'x':
+					code_length = 2
+				case 'u':
+					code_length = 4
+				case 'U':
+					code_length = 8
+				default:
+					yaml_parser_set_scanner_error(parser, "while parsing a quoted scalar",
+						start_mark, "found unknown escape character")
+					return false
+				}
+
+				skip(parser)
+				skip(parser)
+
+				// Consume an arbitrary escape code.
+				if code_length > 0 {
+					var value int
+
+					// Scan the character value.
+					if parser.unread < code_length && !yaml_parser_update_buffer(parser, code_length) {
+						return false
+					}
+					for k := 0; k < code_length; k++ {
+						if !is_hex(parser.buffer, parser.buffer_pos+k) {
+							yaml_parser_set_scanner_error(parser, "while parsing a quoted scalar",
+								start_mark, "did not find expected hexdecimal number")
+							return false
+						}
+						value = (value << 4) + as_hex(parser.buffer, parser.buffer_pos+k)
+					}
+
+					// Check the value and write the character.
+					if (value >= 0xD800 && value <= 0xDFFF) || value > 0x10FFFF {
+						yaml_parser_set_scanner_error(parser, "while parsing a quoted scalar",
+							start_mark, "found invalid Unicode character escape code")
+						return false
+					}
+					if value <= 0x7F {
+						s = append(s, byte(value))
+					} else if value <= 0x7FF {
+						s = append(s, byte(0xC0+(value>>6)))
+						s = append(s, byte(0x80+(value&0x3F)))
+					} else if value <= 0xFFFF {
+						s = append(s, byte(0xE0+(value>>12)))
+						s = append(s, byte(0x80+((value>>6)&0x3F)))
+						s = append(s, byte(0x80+(value&0x3F)))
+					} else {
+						s = append(s, byte(0xF0+(value>>18)))
+						s = append(s, byte(0x80+((value>>12)&0x3F)))
+						s = append(s, byte(0x80+((value>>6)&0x3F)))
+						s = append(s, byte(0x80+(value&0x3F)))
+					}
+
+					// Advance the pointer.
+					for k := 0; k < code_length; k++ {
+						skip(parser)
+					}
+				}
+			} else {
+				// It is a non-escaped non-blank character.
+				s = read(parser, s)
+			}
+			if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+				return false
+			}
+		}
+
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+
+		// Check if we are at the end of the scalar.
+		if single {
+			if parser.buffer[parser.buffer_pos] == '\'' {
+				break
+			}
+		} else {
+			if parser.buffer[parser.buffer_pos] == '"' {
+				break
+			}
+		}
+
+		// Consume blank characters.
+		for is_blank(parser.buffer, parser.buffer_pos) || is_break(parser.buffer, parser.buffer_pos) {
+			if is_blank(parser.buffer, parser.buffer_pos) {
+				// Consume a space or a tab character.
+				if !leading_blanks {
+					whitespaces = read(parser, whitespaces)
+				} else {
+					skip(parser)
+				}
+			} else {
+				if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+					return false
+				}
+
+				// Check if it is a first line break.
+				if !leading_blanks {
+					whitespaces = whitespaces[:0]
+					leading_break = read_line(parser, leading_break)
+					leading_blanks = true
+				} else {
+					trailing_breaks = read_line(parser, trailing_breaks)
+				}
+			}
+			if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+				return false
+			}
+		}
+
+		// Join the whitespaces or fold line breaks.
+		if leading_blanks {
+			// Do we need to fold line breaks?
+			if len(leading_break) > 0 && leading_break[0] == '\n' {
+				if len(trailing_breaks) == 0 {
+					s = append(s, ' ')
+				} else {
+					s = append(s, trailing_breaks...)
+				}
+			} else {
+				s = append(s, leading_break...)
+				s = append(s, trailing_breaks...)
+			}
+			trailing_breaks = trailing_breaks[:0]
+			leading_break = leading_break[:0]
+		} else {
+			s = append(s, whitespaces...)
+			whitespaces = whitespaces[:0]
+		}
+	}
+
+	// Eat the right quote.
+	skip(parser)
+	end_mark := parser.mark
+
+	// Create a token.
+	*token = yaml_token_t{
+		typ:        yaml_SCALAR_TOKEN,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+		value:      s,
+		style:      yaml_SINGLE_QUOTED_SCALAR_STYLE,
+	}
+	if !single {
+		token.style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+	}
+	return true
+}
+
+// Scan a plain scalar.
+func yaml_parser_scan_plain_scalar(parser *yaml_parser_t, token *yaml_token_t) bool {
+
+	var s, leading_break, trailing_breaks, whitespaces []byte
+	var leading_blanks bool
+	var indent = parser.indent + 1
+
+	start_mark := parser.mark
+	end_mark := parser.mark
+
+	// Consume the content of the plain scalar.
+	for {
+		// Check for a document indicator.
+		if parser.unread < 4 && !yaml_parser_update_buffer(parser, 4) {
+			return false
+		}
+		if parser.mark.column == 0 &&
+			((parser.buffer[parser.buffer_pos+0] == '-' &&
+				parser.buffer[parser.buffer_pos+1] == '-' &&
+				parser.buffer[parser.buffer_pos+2] == '-') ||
+				(parser.buffer[parser.buffer_pos+0] == '.' &&
+					parser.buffer[parser.buffer_pos+1] == '.' &&
+					parser.buffer[parser.buffer_pos+2] == '.')) &&
+			is_blankz(parser.buffer, parser.buffer_pos+3) {
+			break
+		}
+
+		// Check for a comment.
+		if parser.buffer[parser.buffer_pos] == '#' {
+			break
+		}
+
+		// Consume non-blank characters.
+		for !is_blankz(parser.buffer, parser.buffer_pos) {
+
+			// Check for indicators that may end a plain scalar.
+			if (parser.buffer[parser.buffer_pos] == ':' && is_blankz(parser.buffer, parser.buffer_pos+1)) ||
+				(parser.flow_level > 0 &&
+					(parser.buffer[parser.buffer_pos] == ',' ||
+						parser.buffer[parser.buffer_pos] == '?' || parser.buffer[parser.buffer_pos] == '[' ||
+						parser.buffer[parser.buffer_pos] == ']' || parser.buffer[parser.buffer_pos] == '{' ||
+						parser.buffer[parser.buffer_pos] == '}')) {
+				break
+			}
+
+			// Check if we need to join whitespaces and breaks.
+			if leading_blanks || len(whitespaces) > 0 {
+				if leading_blanks {
+					// Do we need to fold line breaks?
+					if leading_break[0] == '\n' {
+						if len(trailing_breaks) == 0 {
+							s = append(s, ' ')
+						} else {
+							s = append(s, trailing_breaks...)
+						}
+					} else {
+						s = append(s, leading_break...)
+						s = append(s, trailing_breaks...)
+					}
+					trailing_breaks = trailing_breaks[:0]
+					leading_break = leading_break[:0]
+					leading_blanks = false
+				} else {
+					s = append(s, whitespaces...)
+					whitespaces = whitespaces[:0]
+				}
+			}
+
+			// Copy the character.
+			s = read(parser, s)
+
+			end_mark = parser.mark
+			if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+				return false
+			}
+		}
+
+		// Is it the end?
+		if !(is_blank(parser.buffer, parser.buffer_pos) || is_break(parser.buffer, parser.buffer_pos)) {
+			break
+		}
+
+		// Consume blank characters.
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+
+		for is_blank(parser.buffer, parser.buffer_pos) || is_break(parser.buffer, parser.buffer_pos) {
+			if is_blank(parser.buffer, parser.buffer_pos) {
+
+				// Check for tab characters that abuse indentation.
+				if leading_blanks && parser.mark.column < indent && is_tab(parser.buffer, parser.buffer_pos) {
+					yaml_parser_set_scanner_error(parser, "while scanning a plain scalar",
+						start_mark, "found a tab character that violates indentation")
+					return false
+				}
+
+				// Consume a space or a tab character.
+				if !leading_blanks {
+					whitespaces = read(parser, whitespaces)
+				} else {
+					skip(parser)
+				}
+			} else {
+				if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+					return false
+				}
+
+				// Check if it is a first line break.
+				if !leading_blanks {
+					whitespaces = whitespaces[:0]
+					leading_break = read_line(parser, leading_break)
+					leading_blanks = true
+				} else {
+					trailing_breaks = read_line(parser, trailing_breaks)
+				}
+			}
+			if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+				return false
+			}
+		}
+
+		// Check indentation level.
+		if parser.flow_level == 0 && parser.mark.column < indent {
+			break
+		}
+	}
+
+	// Create a token.
+	*token = yaml_token_t{
+		typ:        yaml_SCALAR_TOKEN,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+		value:      s,
+		style:      yaml_PLAIN_SCALAR_STYLE,
+	}
+
+	// Note that we change the 'simple_key_allowed' flag.
+	if leading_blanks {
+		parser.simple_key_allowed = true
+	}
+	return true
+}
diff --git a/vendor/gopkg.in/yaml.v2/sorter.go b/vendor/gopkg.in/yaml.v2/sorter.go
new file mode 100644
index 0000000..4c45e66
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/sorter.go
@@ -0,0 +1,113 @@
+package yaml
+
+import (
+	"reflect"
+	"unicode"
+)
+
+type keyList []reflect.Value
+
+func (l keyList) Len() int      { return len(l) }
+func (l keyList) Swap(i, j int) { l[i], l[j] = l[j], l[i] }
+func (l keyList) Less(i, j int) bool {
+	a := l[i]
+	b := l[j]
+	ak := a.Kind()
+	bk := b.Kind()
+	for (ak == reflect.Interface || ak == reflect.Ptr) && !a.IsNil() {
+		a = a.Elem()
+		ak = a.Kind()
+	}
+	for (bk == reflect.Interface || bk == reflect.Ptr) && !b.IsNil() {
+		b = b.Elem()
+		bk = b.Kind()
+	}
+	af, aok := keyFloat(a)
+	bf, bok := keyFloat(b)
+	if aok && bok {
+		if af != bf {
+			return af < bf
+		}
+		if ak != bk {
+			return ak < bk
+		}
+		return numLess(a, b)
+	}
+	if ak != reflect.String || bk != reflect.String {
+		return ak < bk
+	}
+	ar, br := []rune(a.String()), []rune(b.String())
+	for i := 0; i < len(ar) && i < len(br); i++ {
+		if ar[i] == br[i] {
+			continue
+		}
+		al := unicode.IsLetter(ar[i])
+		bl := unicode.IsLetter(br[i])
+		if al && bl {
+			return ar[i] < br[i]
+		}
+		if al || bl {
+			return bl
+		}
+		var ai, bi int
+		var an, bn int64
+		if ar[i] == '0' || br[i] == '0' {
+			for j := i-1; j >= 0 && unicode.IsDigit(ar[j]); j-- {
+				if ar[j] != '0' {
+					an = 1
+					bn = 1
+					break
+				}
+			}
+		}
+		for ai = i; ai < len(ar) && unicode.IsDigit(ar[ai]); ai++ {
+			an = an*10 + int64(ar[ai]-'0')
+		}
+		for bi = i; bi < len(br) && unicode.IsDigit(br[bi]); bi++ {
+			bn = bn*10 + int64(br[bi]-'0')
+		}
+		if an != bn {
+			return an < bn
+		}
+		if ai != bi {
+			return ai < bi
+		}
+		return ar[i] < br[i]
+	}
+	return len(ar) < len(br)
+}
+
+// keyFloat returns a float value for v if it is a number/bool
+// and whether it is a number/bool or not.
+func keyFloat(v reflect.Value) (f float64, ok bool) {
+	switch v.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return float64(v.Int()), true
+	case reflect.Float32, reflect.Float64:
+		return v.Float(), true
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return float64(v.Uint()), true
+	case reflect.Bool:
+		if v.Bool() {
+			return 1, true
+		}
+		return 0, true
+	}
+	return 0, false
+}
+
+// numLess returns whether a < b.
+// a and b must necessarily have the same kind.
+func numLess(a, b reflect.Value) bool {
+	switch a.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return a.Int() < b.Int()
+	case reflect.Float32, reflect.Float64:
+		return a.Float() < b.Float()
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return a.Uint() < b.Uint()
+	case reflect.Bool:
+		return !a.Bool() && b.Bool()
+	}
+	panic("not a number")
+}
diff --git a/vendor/gopkg.in/yaml.v2/writerc.go b/vendor/gopkg.in/yaml.v2/writerc.go
new file mode 100644
index 0000000..a2dde60
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/writerc.go
@@ -0,0 +1,26 @@
+package yaml
+
+// Set the writer error and return false.
+func yaml_emitter_set_writer_error(emitter *yaml_emitter_t, problem string) bool {
+	emitter.error = yaml_WRITER_ERROR
+	emitter.problem = problem
+	return false
+}
+
+// Flush the output buffer.
+func yaml_emitter_flush(emitter *yaml_emitter_t) bool {
+	if emitter.write_handler == nil {
+		panic("write handler not set")
+	}
+
+	// Check if the buffer is empty.
+	if emitter.buffer_pos == 0 {
+		return true
+	}
+
+	if err := emitter.write_handler(emitter, emitter.buffer[:emitter.buffer_pos]); err != nil {
+		return yaml_emitter_set_writer_error(emitter, "write error: "+err.Error())
+	}
+	emitter.buffer_pos = 0
+	return true
+}
diff --git a/vendor/gopkg.in/yaml.v2/yaml.go b/vendor/gopkg.in/yaml.v2/yaml.go
new file mode 100644
index 0000000..de85aa4
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/yaml.go
@@ -0,0 +1,466 @@
+// Package yaml implements YAML support for the Go language.
+//
+// Source code and other details for the project are available at GitHub:
+//
+//   https://github.com/go-yaml/yaml
+//
+package yaml
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"reflect"
+	"strings"
+	"sync"
+)
+
+// MapSlice encodes and decodes as a YAML map.
+// The order of keys is preserved when encoding and decoding.
+type MapSlice []MapItem
+
+// MapItem is an item in a MapSlice.
+type MapItem struct {
+	Key, Value interface{}
+}
+
+// The Unmarshaler interface may be implemented by types to customize their
+// behavior when being unmarshaled from a YAML document. The UnmarshalYAML
+// method receives a function that may be called to unmarshal the original
+// YAML value into a field or variable. It is safe to call the unmarshal
+// function parameter more than once if necessary.
+type Unmarshaler interface {
+	UnmarshalYAML(unmarshal func(interface{}) error) error
+}
+
+// The Marshaler interface may be implemented by types to customize their
+// behavior when being marshaled into a YAML document. The returned value
+// is marshaled in place of the original value implementing Marshaler.
+//
+// If an error is returned by MarshalYAML, the marshaling procedure stops
+// and returns with the provided error.
+type Marshaler interface {
+	MarshalYAML() (interface{}, error)
+}
+
+// Unmarshal decodes the first document found within the in byte slice
+// and assigns decoded values into the out value.
+//
+// Maps and pointers (to a struct, string, int, etc) are accepted as out
+// values. If an internal pointer within a struct is not initialized,
+// the yaml package will initialize it if necessary for unmarshalling
+// the provided data. The out parameter must not be nil.
+//
+// The type of the decoded values should be compatible with the respective
+// values in out. If one or more values cannot be decoded due to a type
+// mismatches, decoding continues partially until the end of the YAML
+// content, and a *yaml.TypeError is returned with details for all
+// missed values.
+//
+// Struct fields are only unmarshalled if they are exported (have an
+// upper case first letter), and are unmarshalled using the field name
+// lowercased as the default key. Custom keys may be defined via the
+// "yaml" name in the field tag: the content preceding the first comma
+// is used as the key, and the following comma-separated options are
+// used to tweak the marshalling process (see Marshal).
+// Conflicting names result in a runtime error.
+//
+// For example:
+//
+//     type T struct {
+//         F int `yaml:"a,omitempty"`
+//         B int
+//     }
+//     var t T
+//     yaml.Unmarshal([]byte("a: 1\nb: 2"), &t)
+//
+// See the documentation of Marshal for the format of tags and a list of
+// supported tag options.
+//
+func Unmarshal(in []byte, out interface{}) (err error) {
+	return unmarshal(in, out, false)
+}
+
+// UnmarshalStrict is like Unmarshal except that any fields that are found
+// in the data that do not have corresponding struct members, or mapping
+// keys that are duplicates, will result in
+// an error.
+func UnmarshalStrict(in []byte, out interface{}) (err error) {
+	return unmarshal(in, out, true)
+}
+
+// A Decorder reads and decodes YAML values from an input stream.
+type Decoder struct {
+	strict bool
+	parser *parser
+}
+
+// NewDecoder returns a new decoder that reads from r.
+//
+// The decoder introduces its own buffering and may read
+// data from r beyond the YAML values requested.
+func NewDecoder(r io.Reader) *Decoder {
+	return &Decoder{
+		parser: newParserFromReader(r),
+	}
+}
+
+// SetStrict sets whether strict decoding behaviour is enabled when
+// decoding items in the data (see UnmarshalStrict). By default, decoding is not strict.
+func (dec *Decoder) SetStrict(strict bool) {
+	dec.strict = strict
+}
+
+// Decode reads the next YAML-encoded value from its input
+// and stores it in the value pointed to by v.
+//
+// See the documentation for Unmarshal for details about the
+// conversion of YAML into a Go value.
+func (dec *Decoder) Decode(v interface{}) (err error) {
+	d := newDecoder(dec.strict)
+	defer handleErr(&err)
+	node := dec.parser.parse()
+	if node == nil {
+		return io.EOF
+	}
+	out := reflect.ValueOf(v)
+	if out.Kind() == reflect.Ptr && !out.IsNil() {
+		out = out.Elem()
+	}
+	d.unmarshal(node, out)
+	if len(d.terrors) > 0 {
+		return &TypeError{d.terrors}
+	}
+	return nil
+}
+
+func unmarshal(in []byte, out interface{}, strict bool) (err error) {
+	defer handleErr(&err)
+	d := newDecoder(strict)
+	p := newParser(in)
+	defer p.destroy()
+	node := p.parse()
+	if node != nil {
+		v := reflect.ValueOf(out)
+		if v.Kind() == reflect.Ptr && !v.IsNil() {
+			v = v.Elem()
+		}
+		d.unmarshal(node, v)
+	}
+	if len(d.terrors) > 0 {
+		return &TypeError{d.terrors}
+	}
+	return nil
+}
+
+// Marshal serializes the value provided into a YAML document. The structure
+// of the generated document will reflect the structure of the value itself.
+// Maps and pointers (to struct, string, int, etc) are accepted as the in value.
+//
+// Struct fields are only marshalled if they are exported (have an upper case
+// first letter), and are marshalled using the field name lowercased as the
+// default key. Custom keys may be defined via the "yaml" name in the field
+// tag: the content preceding the first comma is used as the key, and the
+// following comma-separated options are used to tweak the marshalling process.
+// Conflicting names result in a runtime error.
+//
+// The field tag format accepted is:
+//
+//     `(...) yaml:"[<key>][,<flag1>[,<flag2>]]" (...)`
+//
+// The following flags are currently supported:
+//
+//     omitempty    Only include the field if it's not set to the zero
+//                  value for the type or to empty slices or maps.
+//                  Zero valued structs will be omitted if all their public
+//                  fields are zero, unless they implement an IsZero
+//                  method (see the IsZeroer interface type), in which
+//                  case the field will be included if that method returns true.
+//
+//     flow         Marshal using a flow style (useful for structs,
+//                  sequences and maps).
+//
+//     inline       Inline the field, which must be a struct or a map,
+//                  causing all of its fields or keys to be processed as if
+//                  they were part of the outer struct. For maps, keys must
+//                  not conflict with the yaml keys of other struct fields.
+//
+// In addition, if the key is "-", the field is ignored.
+//
+// For example:
+//
+//     type T struct {
+//         F int `yaml:"a,omitempty"`
+//         B int
+//     }
+//     yaml.Marshal(&T{B: 2}) // Returns "b: 2\n"
+//     yaml.Marshal(&T{F: 1}} // Returns "a: 1\nb: 0\n"
+//
+func Marshal(in interface{}) (out []byte, err error) {
+	defer handleErr(&err)
+	e := newEncoder()
+	defer e.destroy()
+	e.marshalDoc("", reflect.ValueOf(in))
+	e.finish()
+	out = e.out
+	return
+}
+
+// An Encoder writes YAML values to an output stream.
+type Encoder struct {
+	encoder *encoder
+}
+
+// NewEncoder returns a new encoder that writes to w.
+// The Encoder should be closed after use to flush all data
+// to w.
+func NewEncoder(w io.Writer) *Encoder {
+	return &Encoder{
+		encoder: newEncoderWithWriter(w),
+	}
+}
+
+// Encode writes the YAML encoding of v to the stream.
+// If multiple items are encoded to the stream, the
+// second and subsequent document will be preceded
+// with a "---" document separator, but the first will not.
+//
+// See the documentation for Marshal for details about the conversion of Go
+// values to YAML.
+func (e *Encoder) Encode(v interface{}) (err error) {
+	defer handleErr(&err)
+	e.encoder.marshalDoc("", reflect.ValueOf(v))
+	return nil
+}
+
+// Close closes the encoder by writing any remaining data.
+// It does not write a stream terminating string "...".
+func (e *Encoder) Close() (err error) {
+	defer handleErr(&err)
+	e.encoder.finish()
+	return nil
+}
+
+func handleErr(err *error) {
+	if v := recover(); v != nil {
+		if e, ok := v.(yamlError); ok {
+			*err = e.err
+		} else {
+			panic(v)
+		}
+	}
+}
+
+type yamlError struct {
+	err error
+}
+
+func fail(err error) {
+	panic(yamlError{err})
+}
+
+func failf(format string, args ...interface{}) {
+	panic(yamlError{fmt.Errorf("yaml: "+format, args...)})
+}
+
+// A TypeError is returned by Unmarshal when one or more fields in
+// the YAML document cannot be properly decoded into the requested
+// types. When this error is returned, the value is still
+// unmarshaled partially.
+type TypeError struct {
+	Errors []string
+}
+
+func (e *TypeError) Error() string {
+	return fmt.Sprintf("yaml: unmarshal errors:\n  %s", strings.Join(e.Errors, "\n  "))
+}
+
+// --------------------------------------------------------------------------
+// Maintain a mapping of keys to structure field indexes
+
+// The code in this section was copied from mgo/bson.
+
+// structInfo holds details for the serialization of fields of
+// a given struct.
+type structInfo struct {
+	FieldsMap  map[string]fieldInfo
+	FieldsList []fieldInfo
+
+	// InlineMap is the number of the field in the struct that
+	// contains an ,inline map, or -1 if there's none.
+	InlineMap int
+}
+
+type fieldInfo struct {
+	Key       string
+	Num       int
+	OmitEmpty bool
+	Flow      bool
+	// Id holds the unique field identifier, so we can cheaply
+	// check for field duplicates without maintaining an extra map.
+	Id int
+
+	// Inline holds the field index if the field is part of an inlined struct.
+	Inline []int
+}
+
+var structMap = make(map[reflect.Type]*structInfo)
+var fieldMapMutex sync.RWMutex
+
+func getStructInfo(st reflect.Type) (*structInfo, error) {
+	fieldMapMutex.RLock()
+	sinfo, found := structMap[st]
+	fieldMapMutex.RUnlock()
+	if found {
+		return sinfo, nil
+	}
+
+	n := st.NumField()
+	fieldsMap := make(map[string]fieldInfo)
+	fieldsList := make([]fieldInfo, 0, n)
+	inlineMap := -1
+	for i := 0; i != n; i++ {
+		field := st.Field(i)
+		if field.PkgPath != "" && !field.Anonymous {
+			continue // Private field
+		}
+
+		info := fieldInfo{Num: i}
+
+		tag := field.Tag.Get("yaml")
+		if tag == "" && strings.Index(string(field.Tag), ":") < 0 {
+			tag = string(field.Tag)
+		}
+		if tag == "-" {
+			continue
+		}
+
+		inline := false
+		fields := strings.Split(tag, ",")
+		if len(fields) > 1 {
+			for _, flag := range fields[1:] {
+				switch flag {
+				case "omitempty":
+					info.OmitEmpty = true
+				case "flow":
+					info.Flow = true
+				case "inline":
+					inline = true
+				default:
+					return nil, errors.New(fmt.Sprintf("Unsupported flag %q in tag %q of type %s", flag, tag, st))
+				}
+			}
+			tag = fields[0]
+		}
+
+		if inline {
+			switch field.Type.Kind() {
+			case reflect.Map:
+				if inlineMap >= 0 {
+					return nil, errors.New("Multiple ,inline maps in struct " + st.String())
+				}
+				if field.Type.Key() != reflect.TypeOf("") {
+					return nil, errors.New("Option ,inline needs a map with string keys in struct " + st.String())
+				}
+				inlineMap = info.Num
+			case reflect.Struct:
+				sinfo, err := getStructInfo(field.Type)
+				if err != nil {
+					return nil, err
+				}
+				for _, finfo := range sinfo.FieldsList {
+					if _, found := fieldsMap[finfo.Key]; found {
+						msg := "Duplicated key '" + finfo.Key + "' in struct " + st.String()
+						return nil, errors.New(msg)
+					}
+					if finfo.Inline == nil {
+						finfo.Inline = []int{i, finfo.Num}
+					} else {
+						finfo.Inline = append([]int{i}, finfo.Inline...)
+					}
+					finfo.Id = len(fieldsList)
+					fieldsMap[finfo.Key] = finfo
+					fieldsList = append(fieldsList, finfo)
+				}
+			default:
+				//return nil, errors.New("Option ,inline needs a struct value or map field")
+				return nil, errors.New("Option ,inline needs a struct value field")
+			}
+			continue
+		}
+
+		if tag != "" {
+			info.Key = tag
+		} else {
+			info.Key = strings.ToLower(field.Name)
+		}
+
+		if _, found = fieldsMap[info.Key]; found {
+			msg := "Duplicated key '" + info.Key + "' in struct " + st.String()
+			return nil, errors.New(msg)
+		}
+
+		info.Id = len(fieldsList)
+		fieldsList = append(fieldsList, info)
+		fieldsMap[info.Key] = info
+	}
+
+	sinfo = &structInfo{
+		FieldsMap:  fieldsMap,
+		FieldsList: fieldsList,
+		InlineMap:  inlineMap,
+	}
+
+	fieldMapMutex.Lock()
+	structMap[st] = sinfo
+	fieldMapMutex.Unlock()
+	return sinfo, nil
+}
+
+// IsZeroer is used to check whether an object is zero to
+// determine whether it should be omitted when marshaling
+// with the omitempty flag. One notable implementation
+// is time.Time.
+type IsZeroer interface {
+	IsZero() bool
+}
+
+func isZero(v reflect.Value) bool {
+	kind := v.Kind()
+	if z, ok := v.Interface().(IsZeroer); ok {
+		if (kind == reflect.Ptr || kind == reflect.Interface) && v.IsNil() {
+			return true
+		}
+		return z.IsZero()
+	}
+	switch kind {
+	case reflect.String:
+		return len(v.String()) == 0
+	case reflect.Interface, reflect.Ptr:
+		return v.IsNil()
+	case reflect.Slice:
+		return v.Len() == 0
+	case reflect.Map:
+		return v.Len() == 0
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return v.Int() == 0
+	case reflect.Float32, reflect.Float64:
+		return v.Float() == 0
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return v.Uint() == 0
+	case reflect.Bool:
+		return !v.Bool()
+	case reflect.Struct:
+		vt := v.Type()
+		for i := v.NumField() - 1; i >= 0; i-- {
+			if vt.Field(i).PkgPath != "" {
+				continue // Private field
+			}
+			if !isZero(v.Field(i)) {
+				return false
+			}
+		}
+		return true
+	}
+	return false
+}
diff --git a/vendor/gopkg.in/yaml.v2/yamlh.go b/vendor/gopkg.in/yaml.v2/yamlh.go
new file mode 100644
index 0000000..e25cee5
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/yamlh.go
@@ -0,0 +1,738 @@
+package yaml
+
+import (
+	"fmt"
+	"io"
+)
+
+// The version directive data.
+type yaml_version_directive_t struct {
+	major int8 // The major version number.
+	minor int8 // The minor version number.
+}
+
+// The tag directive data.
+type yaml_tag_directive_t struct {
+	handle []byte // The tag handle.
+	prefix []byte // The tag prefix.
+}
+
+type yaml_encoding_t int
+
+// The stream encoding.
+const (
+	// Let the parser choose the encoding.
+	yaml_ANY_ENCODING yaml_encoding_t = iota
+
+	yaml_UTF8_ENCODING    // The default UTF-8 encoding.
+	yaml_UTF16LE_ENCODING // The UTF-16-LE encoding with BOM.
+	yaml_UTF16BE_ENCODING // The UTF-16-BE encoding with BOM.
+)
+
+type yaml_break_t int
+
+// Line break types.
+const (
+	// Let the parser choose the break type.
+	yaml_ANY_BREAK yaml_break_t = iota
+
+	yaml_CR_BREAK   // Use CR for line breaks (Mac style).
+	yaml_LN_BREAK   // Use LN for line breaks (Unix style).
+	yaml_CRLN_BREAK // Use CR LN for line breaks (DOS style).
+)
+
+type yaml_error_type_t int
+
+// Many bad things could happen with the parser and emitter.
+const (
+	// No error is produced.
+	yaml_NO_ERROR yaml_error_type_t = iota
+
+	yaml_MEMORY_ERROR   // Cannot allocate or reallocate a block of memory.
+	yaml_READER_ERROR   // Cannot read or decode the input stream.
+	yaml_SCANNER_ERROR  // Cannot scan the input stream.
+	yaml_PARSER_ERROR   // Cannot parse the input stream.
+	yaml_COMPOSER_ERROR // Cannot compose a YAML document.
+	yaml_WRITER_ERROR   // Cannot write to the output stream.
+	yaml_EMITTER_ERROR  // Cannot emit a YAML stream.
+)
+
+// The pointer position.
+type yaml_mark_t struct {
+	index  int // The position index.
+	line   int // The position line.
+	column int // The position column.
+}
+
+// Node Styles
+
+type yaml_style_t int8
+
+type yaml_scalar_style_t yaml_style_t
+
+// Scalar styles.
+const (
+	// Let the emitter choose the style.
+	yaml_ANY_SCALAR_STYLE yaml_scalar_style_t = iota
+
+	yaml_PLAIN_SCALAR_STYLE         // The plain scalar style.
+	yaml_SINGLE_QUOTED_SCALAR_STYLE // The single-quoted scalar style.
+	yaml_DOUBLE_QUOTED_SCALAR_STYLE // The double-quoted scalar style.
+	yaml_LITERAL_SCALAR_STYLE       // The literal scalar style.
+	yaml_FOLDED_SCALAR_STYLE        // The folded scalar style.
+)
+
+type yaml_sequence_style_t yaml_style_t
+
+// Sequence styles.
+const (
+	// Let the emitter choose the style.
+	yaml_ANY_SEQUENCE_STYLE yaml_sequence_style_t = iota
+
+	yaml_BLOCK_SEQUENCE_STYLE // The block sequence style.
+	yaml_FLOW_SEQUENCE_STYLE  // The flow sequence style.
+)
+
+type yaml_mapping_style_t yaml_style_t
+
+// Mapping styles.
+const (
+	// Let the emitter choose the style.
+	yaml_ANY_MAPPING_STYLE yaml_mapping_style_t = iota
+
+	yaml_BLOCK_MAPPING_STYLE // The block mapping style.
+	yaml_FLOW_MAPPING_STYLE  // The flow mapping style.
+)
+
+// Tokens
+
+type yaml_token_type_t int
+
+// Token types.
+const (
+	// An empty token.
+	yaml_NO_TOKEN yaml_token_type_t = iota
+
+	yaml_STREAM_START_TOKEN // A STREAM-START token.
+	yaml_STREAM_END_TOKEN   // A STREAM-END token.
+
+	yaml_VERSION_DIRECTIVE_TOKEN // A VERSION-DIRECTIVE token.
+	yaml_TAG_DIRECTIVE_TOKEN     // A TAG-DIRECTIVE token.
+	yaml_DOCUMENT_START_TOKEN    // A DOCUMENT-START token.
+	yaml_DOCUMENT_END_TOKEN      // A DOCUMENT-END token.
+
+	yaml_BLOCK_SEQUENCE_START_TOKEN // A BLOCK-SEQUENCE-START token.
+	yaml_BLOCK_MAPPING_START_TOKEN  // A BLOCK-SEQUENCE-END token.
+	yaml_BLOCK_END_TOKEN            // A BLOCK-END token.
+
+	yaml_FLOW_SEQUENCE_START_TOKEN // A FLOW-SEQUENCE-START token.
+	yaml_FLOW_SEQUENCE_END_TOKEN   // A FLOW-SEQUENCE-END token.
+	yaml_FLOW_MAPPING_START_TOKEN  // A FLOW-MAPPING-START token.
+	yaml_FLOW_MAPPING_END_TOKEN    // A FLOW-MAPPING-END token.
+
+	yaml_BLOCK_ENTRY_TOKEN // A BLOCK-ENTRY token.
+	yaml_FLOW_ENTRY_TOKEN  // A FLOW-ENTRY token.
+	yaml_KEY_TOKEN         // A KEY token.
+	yaml_VALUE_TOKEN       // A VALUE token.
+
+	yaml_ALIAS_TOKEN  // An ALIAS token.
+	yaml_ANCHOR_TOKEN // An ANCHOR token.
+	yaml_TAG_TOKEN    // A TAG token.
+	yaml_SCALAR_TOKEN // A SCALAR token.
+)
+
+func (tt yaml_token_type_t) String() string {
+	switch tt {
+	case yaml_NO_TOKEN:
+		return "yaml_NO_TOKEN"
+	case yaml_STREAM_START_TOKEN:
+		return "yaml_STREAM_START_TOKEN"
+	case yaml_STREAM_END_TOKEN:
+		return "yaml_STREAM_END_TOKEN"
+	case yaml_VERSION_DIRECTIVE_TOKEN:
+		return "yaml_VERSION_DIRECTIVE_TOKEN"
+	case yaml_TAG_DIRECTIVE_TOKEN:
+		return "yaml_TAG_DIRECTIVE_TOKEN"
+	case yaml_DOCUMENT_START_TOKEN:
+		return "yaml_DOCUMENT_START_TOKEN"
+	case yaml_DOCUMENT_END_TOKEN:
+		return "yaml_DOCUMENT_END_TOKEN"
+	case yaml_BLOCK_SEQUENCE_START_TOKEN:
+		return "yaml_BLOCK_SEQUENCE_START_TOKEN"
+	case yaml_BLOCK_MAPPING_START_TOKEN:
+		return "yaml_BLOCK_MAPPING_START_TOKEN"
+	case yaml_BLOCK_END_TOKEN:
+		return "yaml_BLOCK_END_TOKEN"
+	case yaml_FLOW_SEQUENCE_START_TOKEN:
+		return "yaml_FLOW_SEQUENCE_START_TOKEN"
+	case yaml_FLOW_SEQUENCE_END_TOKEN:
+		return "yaml_FLOW_SEQUENCE_END_TOKEN"
+	case yaml_FLOW_MAPPING_START_TOKEN:
+		return "yaml_FLOW_MAPPING_START_TOKEN"
+	case yaml_FLOW_MAPPING_END_TOKEN:
+		return "yaml_FLOW_MAPPING_END_TOKEN"
+	case yaml_BLOCK_ENTRY_TOKEN:
+		return "yaml_BLOCK_ENTRY_TOKEN"
+	case yaml_FLOW_ENTRY_TOKEN:
+		return "yaml_FLOW_ENTRY_TOKEN"
+	case yaml_KEY_TOKEN:
+		return "yaml_KEY_TOKEN"
+	case yaml_VALUE_TOKEN:
+		return "yaml_VALUE_TOKEN"
+	case yaml_ALIAS_TOKEN:
+		return "yaml_ALIAS_TOKEN"
+	case yaml_ANCHOR_TOKEN:
+		return "yaml_ANCHOR_TOKEN"
+	case yaml_TAG_TOKEN:
+		return "yaml_TAG_TOKEN"
+	case yaml_SCALAR_TOKEN:
+		return "yaml_SCALAR_TOKEN"
+	}
+	return "<unknown token>"
+}
+
+// The token structure.
+type yaml_token_t struct {
+	// The token type.
+	typ yaml_token_type_t
+
+	// The start/end of the token.
+	start_mark, end_mark yaml_mark_t
+
+	// The stream encoding (for yaml_STREAM_START_TOKEN).
+	encoding yaml_encoding_t
+
+	// The alias/anchor/scalar value or tag/tag directive handle
+	// (for yaml_ALIAS_TOKEN, yaml_ANCHOR_TOKEN, yaml_SCALAR_TOKEN, yaml_TAG_TOKEN, yaml_TAG_DIRECTIVE_TOKEN).
+	value []byte
+
+	// The tag suffix (for yaml_TAG_TOKEN).
+	suffix []byte
+
+	// The tag directive prefix (for yaml_TAG_DIRECTIVE_TOKEN).
+	prefix []byte
+
+	// The scalar style (for yaml_SCALAR_TOKEN).
+	style yaml_scalar_style_t
+
+	// The version directive major/minor (for yaml_VERSION_DIRECTIVE_TOKEN).
+	major, minor int8
+}
+
+// Events
+
+type yaml_event_type_t int8
+
+// Event types.
+const (
+	// An empty event.
+	yaml_NO_EVENT yaml_event_type_t = iota
+
+	yaml_STREAM_START_EVENT   // A STREAM-START event.
+	yaml_STREAM_END_EVENT     // A STREAM-END event.
+	yaml_DOCUMENT_START_EVENT // A DOCUMENT-START event.
+	yaml_DOCUMENT_END_EVENT   // A DOCUMENT-END event.
+	yaml_ALIAS_EVENT          // An ALIAS event.
+	yaml_SCALAR_EVENT         // A SCALAR event.
+	yaml_SEQUENCE_START_EVENT // A SEQUENCE-START event.
+	yaml_SEQUENCE_END_EVENT   // A SEQUENCE-END event.
+	yaml_MAPPING_START_EVENT  // A MAPPING-START event.
+	yaml_MAPPING_END_EVENT    // A MAPPING-END event.
+)
+
+var eventStrings = []string{
+	yaml_NO_EVENT:             "none",
+	yaml_STREAM_START_EVENT:   "stream start",
+	yaml_STREAM_END_EVENT:     "stream end",
+	yaml_DOCUMENT_START_EVENT: "document start",
+	yaml_DOCUMENT_END_EVENT:   "document end",
+	yaml_ALIAS_EVENT:          "alias",
+	yaml_SCALAR_EVENT:         "scalar",
+	yaml_SEQUENCE_START_EVENT: "sequence start",
+	yaml_SEQUENCE_END_EVENT:   "sequence end",
+	yaml_MAPPING_START_EVENT:  "mapping start",
+	yaml_MAPPING_END_EVENT:    "mapping end",
+}
+
+func (e yaml_event_type_t) String() string {
+	if e < 0 || int(e) >= len(eventStrings) {
+		return fmt.Sprintf("unknown event %d", e)
+	}
+	return eventStrings[e]
+}
+
+// The event structure.
+type yaml_event_t struct {
+
+	// The event type.
+	typ yaml_event_type_t
+
+	// The start and end of the event.
+	start_mark, end_mark yaml_mark_t
+
+	// The document encoding (for yaml_STREAM_START_EVENT).
+	encoding yaml_encoding_t
+
+	// The version directive (for yaml_DOCUMENT_START_EVENT).
+	version_directive *yaml_version_directive_t
+
+	// The list of tag directives (for yaml_DOCUMENT_START_EVENT).
+	tag_directives []yaml_tag_directive_t
+
+	// The anchor (for yaml_SCALAR_EVENT, yaml_SEQUENCE_START_EVENT, yaml_MAPPING_START_EVENT, yaml_ALIAS_EVENT).
+	anchor []byte
+
+	// The tag (for yaml_SCALAR_EVENT, yaml_SEQUENCE_START_EVENT, yaml_MAPPING_START_EVENT).
+	tag []byte
+
+	// The scalar value (for yaml_SCALAR_EVENT).
+	value []byte
+
+	// Is the document start/end indicator implicit, or the tag optional?
+	// (for yaml_DOCUMENT_START_EVENT, yaml_DOCUMENT_END_EVENT, yaml_SEQUENCE_START_EVENT, yaml_MAPPING_START_EVENT, yaml_SCALAR_EVENT).
+	implicit bool
+
+	// Is the tag optional for any non-plain style? (for yaml_SCALAR_EVENT).
+	quoted_implicit bool
+
+	// The style (for yaml_SCALAR_EVENT, yaml_SEQUENCE_START_EVENT, yaml_MAPPING_START_EVENT).
+	style yaml_style_t
+}
+
+func (e *yaml_event_t) scalar_style() yaml_scalar_style_t     { return yaml_scalar_style_t(e.style) }
+func (e *yaml_event_t) sequence_style() yaml_sequence_style_t { return yaml_sequence_style_t(e.style) }
+func (e *yaml_event_t) mapping_style() yaml_mapping_style_t   { return yaml_mapping_style_t(e.style) }
+
+// Nodes
+
+const (
+	yaml_NULL_TAG      = "tag:yaml.org,2002:null"      // The tag !!null with the only possible value: null.
+	yaml_BOOL_TAG      = "tag:yaml.org,2002:bool"      // The tag !!bool with the values: true and false.
+	yaml_STR_TAG       = "tag:yaml.org,2002:str"       // The tag !!str for string values.
+	yaml_INT_TAG       = "tag:yaml.org,2002:int"       // The tag !!int for integer values.
+	yaml_FLOAT_TAG     = "tag:yaml.org,2002:float"     // The tag !!float for float values.
+	yaml_TIMESTAMP_TAG = "tag:yaml.org,2002:timestamp" // The tag !!timestamp for date and time values.
+
+	yaml_SEQ_TAG = "tag:yaml.org,2002:seq" // The tag !!seq is used to denote sequences.
+	yaml_MAP_TAG = "tag:yaml.org,2002:map" // The tag !!map is used to denote mapping.
+
+	// Not in original libyaml.
+	yaml_BINARY_TAG = "tag:yaml.org,2002:binary"
+	yaml_MERGE_TAG  = "tag:yaml.org,2002:merge"
+
+	yaml_DEFAULT_SCALAR_TAG   = yaml_STR_TAG // The default scalar tag is !!str.
+	yaml_DEFAULT_SEQUENCE_TAG = yaml_SEQ_TAG // The default sequence tag is !!seq.
+	yaml_DEFAULT_MAPPING_TAG  = yaml_MAP_TAG // The default mapping tag is !!map.
+)
+
+type yaml_node_type_t int
+
+// Node types.
+const (
+	// An empty node.
+	yaml_NO_NODE yaml_node_type_t = iota
+
+	yaml_SCALAR_NODE   // A scalar node.
+	yaml_SEQUENCE_NODE // A sequence node.
+	yaml_MAPPING_NODE  // A mapping node.
+)
+
+// An element of a sequence node.
+type yaml_node_item_t int
+
+// An element of a mapping node.
+type yaml_node_pair_t struct {
+	key   int // The key of the element.
+	value int // The value of the element.
+}
+
+// The node structure.
+type yaml_node_t struct {
+	typ yaml_node_type_t // The node type.
+	tag []byte           // The node tag.
+
+	// The node data.
+
+	// The scalar parameters (for yaml_SCALAR_NODE).
+	scalar struct {
+		value  []byte              // The scalar value.
+		length int                 // The length of the scalar value.
+		style  yaml_scalar_style_t // The scalar style.
+	}
+
+	// The sequence parameters (for YAML_SEQUENCE_NODE).
+	sequence struct {
+		items_data []yaml_node_item_t    // The stack of sequence items.
+		style      yaml_sequence_style_t // The sequence style.
+	}
+
+	// The mapping parameters (for yaml_MAPPING_NODE).
+	mapping struct {
+		pairs_data  []yaml_node_pair_t   // The stack of mapping pairs (key, value).
+		pairs_start *yaml_node_pair_t    // The beginning of the stack.
+		pairs_end   *yaml_node_pair_t    // The end of the stack.
+		pairs_top   *yaml_node_pair_t    // The top of the stack.
+		style       yaml_mapping_style_t // The mapping style.
+	}
+
+	start_mark yaml_mark_t // The beginning of the node.
+	end_mark   yaml_mark_t // The end of the node.
+
+}
+
+// The document structure.
+type yaml_document_t struct {
+
+	// The document nodes.
+	nodes []yaml_node_t
+
+	// The version directive.
+	version_directive *yaml_version_directive_t
+
+	// The list of tag directives.
+	tag_directives_data  []yaml_tag_directive_t
+	tag_directives_start int // The beginning of the tag directives list.
+	tag_directives_end   int // The end of the tag directives list.
+
+	start_implicit int // Is the document start indicator implicit?
+	end_implicit   int // Is the document end indicator implicit?
+
+	// The start/end of the document.
+	start_mark, end_mark yaml_mark_t
+}
+
+// The prototype of a read handler.
+//
+// The read handler is called when the parser needs to read more bytes from the
+// source. The handler should write not more than size bytes to the buffer.
+// The number of written bytes should be set to the size_read variable.
+//
+// [in,out]   data        A pointer to an application data specified by
+//                        yaml_parser_set_input().
+// [out]      buffer      The buffer to write the data from the source.
+// [in]       size        The size of the buffer.
+// [out]      size_read   The actual number of bytes read from the source.
+//
+// On success, the handler should return 1.  If the handler failed,
+// the returned value should be 0. On EOF, the handler should set the
+// size_read to 0 and return 1.
+type yaml_read_handler_t func(parser *yaml_parser_t, buffer []byte) (n int, err error)
+
+// This structure holds information about a potential simple key.
+type yaml_simple_key_t struct {
+	possible     bool        // Is a simple key possible?
+	required     bool        // Is a simple key required?
+	token_number int         // The number of the token.
+	mark         yaml_mark_t // The position mark.
+}
+
+// The states of the parser.
+type yaml_parser_state_t int
+
+const (
+	yaml_PARSE_STREAM_START_STATE yaml_parser_state_t = iota
+
+	yaml_PARSE_IMPLICIT_DOCUMENT_START_STATE           // Expect the beginning of an implicit document.
+	yaml_PARSE_DOCUMENT_START_STATE                    // Expect DOCUMENT-START.
+	yaml_PARSE_DOCUMENT_CONTENT_STATE                  // Expect the content of a document.
+	yaml_PARSE_DOCUMENT_END_STATE                      // Expect DOCUMENT-END.
+	yaml_PARSE_BLOCK_NODE_STATE                        // Expect a block node.
+	yaml_PARSE_BLOCK_NODE_OR_INDENTLESS_SEQUENCE_STATE // Expect a block node or indentless sequence.
+	yaml_PARSE_FLOW_NODE_STATE                         // Expect a flow node.
+	yaml_PARSE_BLOCK_SEQUENCE_FIRST_ENTRY_STATE        // Expect the first entry of a block sequence.
+	yaml_PARSE_BLOCK_SEQUENCE_ENTRY_STATE              // Expect an entry of a block sequence.
+	yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE         // Expect an entry of an indentless sequence.
+	yaml_PARSE_BLOCK_MAPPING_FIRST_KEY_STATE           // Expect the first key of a block mapping.
+	yaml_PARSE_BLOCK_MAPPING_KEY_STATE                 // Expect a block mapping key.
+	yaml_PARSE_BLOCK_MAPPING_VALUE_STATE               // Expect a block mapping value.
+	yaml_PARSE_FLOW_SEQUENCE_FIRST_ENTRY_STATE         // Expect the first entry of a flow sequence.
+	yaml_PARSE_FLOW_SEQUENCE_ENTRY_STATE               // Expect an entry of a flow sequence.
+	yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_KEY_STATE   // Expect a key of an ordered mapping.
+	yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_VALUE_STATE // Expect a value of an ordered mapping.
+	yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_END_STATE   // Expect the and of an ordered mapping entry.
+	yaml_PARSE_FLOW_MAPPING_FIRST_KEY_STATE            // Expect the first key of a flow mapping.
+	yaml_PARSE_FLOW_MAPPING_KEY_STATE                  // Expect a key of a flow mapping.
+	yaml_PARSE_FLOW_MAPPING_VALUE_STATE                // Expect a value of a flow mapping.
+	yaml_PARSE_FLOW_MAPPING_EMPTY_VALUE_STATE          // Expect an empty value of a flow mapping.
+	yaml_PARSE_END_STATE                               // Expect nothing.
+)
+
+func (ps yaml_parser_state_t) String() string {
+	switch ps {
+	case yaml_PARSE_STREAM_START_STATE:
+		return "yaml_PARSE_STREAM_START_STATE"
+	case yaml_PARSE_IMPLICIT_DOCUMENT_START_STATE:
+		return "yaml_PARSE_IMPLICIT_DOCUMENT_START_STATE"
+	case yaml_PARSE_DOCUMENT_START_STATE:
+		return "yaml_PARSE_DOCUMENT_START_STATE"
+	case yaml_PARSE_DOCUMENT_CONTENT_STATE:
+		return "yaml_PARSE_DOCUMENT_CONTENT_STATE"
+	case yaml_PARSE_DOCUMENT_END_STATE:
+		return "yaml_PARSE_DOCUMENT_END_STATE"
+	case yaml_PARSE_BLOCK_NODE_STATE:
+		return "yaml_PARSE_BLOCK_NODE_STATE"
+	case yaml_PARSE_BLOCK_NODE_OR_INDENTLESS_SEQUENCE_STATE:
+		return "yaml_PARSE_BLOCK_NODE_OR_INDENTLESS_SEQUENCE_STATE"
+	case yaml_PARSE_FLOW_NODE_STATE:
+		return "yaml_PARSE_FLOW_NODE_STATE"
+	case yaml_PARSE_BLOCK_SEQUENCE_FIRST_ENTRY_STATE:
+		return "yaml_PARSE_BLOCK_SEQUENCE_FIRST_ENTRY_STATE"
+	case yaml_PARSE_BLOCK_SEQUENCE_ENTRY_STATE:
+		return "yaml_PARSE_BLOCK_SEQUENCE_ENTRY_STATE"
+	case yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE:
+		return "yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE"
+	case yaml_PARSE_BLOCK_MAPPING_FIRST_KEY_STATE:
+		return "yaml_PARSE_BLOCK_MAPPING_FIRST_KEY_STATE"
+	case yaml_PARSE_BLOCK_MAPPING_KEY_STATE:
+		return "yaml_PARSE_BLOCK_MAPPING_KEY_STATE"
+	case yaml_PARSE_BLOCK_MAPPING_VALUE_STATE:
+		return "yaml_PARSE_BLOCK_MAPPING_VALUE_STATE"
+	case yaml_PARSE_FLOW_SEQUENCE_FIRST_ENTRY_STATE:
+		return "yaml_PARSE_FLOW_SEQUENCE_FIRST_ENTRY_STATE"
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_STATE:
+		return "yaml_PARSE_FLOW_SEQUENCE_ENTRY_STATE"
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_KEY_STATE:
+		return "yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_KEY_STATE"
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_VALUE_STATE:
+		return "yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_VALUE_STATE"
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_END_STATE:
+		return "yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_END_STATE"
+	case yaml_PARSE_FLOW_MAPPING_FIRST_KEY_STATE:
+		return "yaml_PARSE_FLOW_MAPPING_FIRST_KEY_STATE"
+	case yaml_PARSE_FLOW_MAPPING_KEY_STATE:
+		return "yaml_PARSE_FLOW_MAPPING_KEY_STATE"
+	case yaml_PARSE_FLOW_MAPPING_VALUE_STATE:
+		return "yaml_PARSE_FLOW_MAPPING_VALUE_STATE"
+	case yaml_PARSE_FLOW_MAPPING_EMPTY_VALUE_STATE:
+		return "yaml_PARSE_FLOW_MAPPING_EMPTY_VALUE_STATE"
+	case yaml_PARSE_END_STATE:
+		return "yaml_PARSE_END_STATE"
+	}
+	return "<unknown parser state>"
+}
+
+// This structure holds aliases data.
+type yaml_alias_data_t struct {
+	anchor []byte      // The anchor.
+	index  int         // The node id.
+	mark   yaml_mark_t // The anchor mark.
+}
+
+// The parser structure.
+//
+// All members are internal. Manage the structure using the
+// yaml_parser_ family of functions.
+type yaml_parser_t struct {
+
+	// Error handling
+
+	error yaml_error_type_t // Error type.
+
+	problem string // Error description.
+
+	// The byte about which the problem occurred.
+	problem_offset int
+	problem_value  int
+	problem_mark   yaml_mark_t
+
+	// The error context.
+	context      string
+	context_mark yaml_mark_t
+
+	// Reader stuff
+
+	read_handler yaml_read_handler_t // Read handler.
+
+	input_reader io.Reader // File input data.
+	input        []byte    // String input data.
+	input_pos    int
+
+	eof bool // EOF flag
+
+	buffer     []byte // The working buffer.
+	buffer_pos int    // The current position of the buffer.
+
+	unread int // The number of unread characters in the buffer.
+
+	raw_buffer     []byte // The raw buffer.
+	raw_buffer_pos int    // The current position of the buffer.
+
+	encoding yaml_encoding_t // The input encoding.
+
+	offset int         // The offset of the current position (in bytes).
+	mark   yaml_mark_t // The mark of the current position.
+
+	// Scanner stuff
+
+	stream_start_produced bool // Have we started to scan the input stream?
+	stream_end_produced   bool // Have we reached the end of the input stream?
+
+	flow_level int // The number of unclosed '[' and '{' indicators.
+
+	tokens          []yaml_token_t // The tokens queue.
+	tokens_head     int            // The head of the tokens queue.
+	tokens_parsed   int            // The number of tokens fetched from the queue.
+	token_available bool           // Does the tokens queue contain a token ready for dequeueing.
+
+	indent  int   // The current indentation level.
+	indents []int // The indentation levels stack.
+
+	simple_key_allowed bool                // May a simple key occur at the current position?
+	simple_keys        []yaml_simple_key_t // The stack of simple keys.
+
+	// Parser stuff
+
+	state          yaml_parser_state_t    // The current parser state.
+	states         []yaml_parser_state_t  // The parser states stack.
+	marks          []yaml_mark_t          // The stack of marks.
+	tag_directives []yaml_tag_directive_t // The list of TAG directives.
+
+	// Dumper stuff
+
+	aliases []yaml_alias_data_t // The alias data.
+
+	document *yaml_document_t // The currently parsed document.
+}
+
+// Emitter Definitions
+
+// The prototype of a write handler.
+//
+// The write handler is called when the emitter needs to flush the accumulated
+// characters to the output.  The handler should write @a size bytes of the
+// @a buffer to the output.
+//
+// @param[in,out]   data        A pointer to an application data specified by
+//                              yaml_emitter_set_output().
+// @param[in]       buffer      The buffer with bytes to be written.
+// @param[in]       size        The size of the buffer.
+//
+// @returns On success, the handler should return @c 1.  If the handler failed,
+// the returned value should be @c 0.
+//
+type yaml_write_handler_t func(emitter *yaml_emitter_t, buffer []byte) error
+
+type yaml_emitter_state_t int
+
+// The emitter states.
+const (
+	// Expect STREAM-START.
+	yaml_EMIT_STREAM_START_STATE yaml_emitter_state_t = iota
+
+	yaml_EMIT_FIRST_DOCUMENT_START_STATE       // Expect the first DOCUMENT-START or STREAM-END.
+	yaml_EMIT_DOCUMENT_START_STATE             // Expect DOCUMENT-START or STREAM-END.
+	yaml_EMIT_DOCUMENT_CONTENT_STATE           // Expect the content of a document.
+	yaml_EMIT_DOCUMENT_END_STATE               // Expect DOCUMENT-END.
+	yaml_EMIT_FLOW_SEQUENCE_FIRST_ITEM_STATE   // Expect the first item of a flow sequence.
+	yaml_EMIT_FLOW_SEQUENCE_ITEM_STATE         // Expect an item of a flow sequence.
+	yaml_EMIT_FLOW_MAPPING_FIRST_KEY_STATE     // Expect the first key of a flow mapping.
+	yaml_EMIT_FLOW_MAPPING_KEY_STATE           // Expect a key of a flow mapping.
+	yaml_EMIT_FLOW_MAPPING_SIMPLE_VALUE_STATE  // Expect a value for a simple key of a flow mapping.
+	yaml_EMIT_FLOW_MAPPING_VALUE_STATE         // Expect a value of a flow mapping.
+	yaml_EMIT_BLOCK_SEQUENCE_FIRST_ITEM_STATE  // Expect the first item of a block sequence.
+	yaml_EMIT_BLOCK_SEQUENCE_ITEM_STATE        // Expect an item of a block sequence.
+	yaml_EMIT_BLOCK_MAPPING_FIRST_KEY_STATE    // Expect the first key of a block mapping.
+	yaml_EMIT_BLOCK_MAPPING_KEY_STATE          // Expect the key of a block mapping.
+	yaml_EMIT_BLOCK_MAPPING_SIMPLE_VALUE_STATE // Expect a value for a simple key of a block mapping.
+	yaml_EMIT_BLOCK_MAPPING_VALUE_STATE        // Expect a value of a block mapping.
+	yaml_EMIT_END_STATE                        // Expect nothing.
+)
+
+// The emitter structure.
+//
+// All members are internal.  Manage the structure using the @c yaml_emitter_
+// family of functions.
+type yaml_emitter_t struct {
+
+	// Error handling
+
+	error   yaml_error_type_t // Error type.
+	problem string            // Error description.
+
+	// Writer stuff
+
+	write_handler yaml_write_handler_t // Write handler.
+
+	output_buffer *[]byte   // String output data.
+	output_writer io.Writer // File output data.
+
+	buffer     []byte // The working buffer.
+	buffer_pos int    // The current position of the buffer.
+
+	raw_buffer     []byte // The raw buffer.
+	raw_buffer_pos int    // The current position of the buffer.
+
+	encoding yaml_encoding_t // The stream encoding.
+
+	// Emitter stuff
+
+	canonical   bool         // If the output is in the canonical style?
+	best_indent int          // The number of indentation spaces.
+	best_width  int          // The preferred width of the output lines.
+	unicode     bool         // Allow unescaped non-ASCII characters?
+	line_break  yaml_break_t // The preferred line break.
+
+	state  yaml_emitter_state_t   // The current emitter state.
+	states []yaml_emitter_state_t // The stack of states.
+
+	events      []yaml_event_t // The event queue.
+	events_head int            // The head of the event queue.
+
+	indents []int // The stack of indentation levels.
+
+	tag_directives []yaml_tag_directive_t // The list of tag directives.
+
+	indent int // The current indentation level.
+
+	flow_level int // The current flow level.
+
+	root_context       bool // Is it the document root context?
+	sequence_context   bool // Is it a sequence context?
+	mapping_context    bool // Is it a mapping context?
+	simple_key_context bool // Is it a simple mapping key context?
+
+	line       int  // The current line.
+	column     int  // The current column.
+	whitespace bool // If the last character was a whitespace?
+	indention  bool // If the last character was an indentation character (' ', '-', '?', ':')?
+	open_ended bool // If an explicit document end is required?
+
+	// Anchor analysis.
+	anchor_data struct {
+		anchor []byte // The anchor value.
+		alias  bool   // Is it an alias?
+	}
+
+	// Tag analysis.
+	tag_data struct {
+		handle []byte // The tag handle.
+		suffix []byte // The tag suffix.
+	}
+
+	// Scalar analysis.
+	scalar_data struct {
+		value                 []byte              // The scalar value.
+		multiline             bool                // Does the scalar contain line breaks?
+		flow_plain_allowed    bool                // Can the scalar be expessed in the flow plain style?
+		block_plain_allowed   bool                // Can the scalar be expressed in the block plain style?
+		single_quoted_allowed bool                // Can the scalar be expressed in the single quoted style?
+		block_allowed         bool                // Can the scalar be expressed in the literal or folded styles?
+		style                 yaml_scalar_style_t // The output style.
+	}
+
+	// Dumper stuff
+
+	opened bool // If the stream was already opened?
+	closed bool // If the stream was already closed?
+
+	// The information associated with the document nodes.
+	anchors *struct {
+		references int  // The number of references.
+		anchor     int  // The anchor id.
+		serialized bool // If the node has been emitted?
+	}
+
+	last_anchor_id int // The last assigned anchor id.
+
+	document *yaml_document_t // The currently emitted document.
+}
diff --git a/vendor/gopkg.in/yaml.v2/yamlprivateh.go b/vendor/gopkg.in/yaml.v2/yamlprivateh.go
new file mode 100644
index 0000000..8110ce3
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/yamlprivateh.go
@@ -0,0 +1,173 @@
+package yaml
+
+const (
+	// The size of the input raw buffer.
+	input_raw_buffer_size = 512
+
+	// The size of the input buffer.
+	// It should be possible to decode the whole raw buffer.
+	input_buffer_size = input_raw_buffer_size * 3
+
+	// The size of the output buffer.
+	output_buffer_size = 128
+
+	// The size of the output raw buffer.
+	// It should be possible to encode the whole output buffer.
+	output_raw_buffer_size = (output_buffer_size*2 + 2)
+
+	// The size of other stacks and queues.
+	initial_stack_size  = 16
+	initial_queue_size  = 16
+	initial_string_size = 16
+)
+
+// Check if the character at the specified position is an alphabetical
+// character, a digit, '_', or '-'.
+func is_alpha(b []byte, i int) bool {
+	return b[i] >= '0' && b[i] <= '9' || b[i] >= 'A' && b[i] <= 'Z' || b[i] >= 'a' && b[i] <= 'z' || b[i] == '_' || b[i] == '-'
+}
+
+// Check if the character at the specified position is a digit.
+func is_digit(b []byte, i int) bool {
+	return b[i] >= '0' && b[i] <= '9'
+}
+
+// Get the value of a digit.
+func as_digit(b []byte, i int) int {
+	return int(b[i]) - '0'
+}
+
+// Check if the character at the specified position is a hex-digit.
+func is_hex(b []byte, i int) bool {
+	return b[i] >= '0' && b[i] <= '9' || b[i] >= 'A' && b[i] <= 'F' || b[i] >= 'a' && b[i] <= 'f'
+}
+
+// Get the value of a hex-digit.
+func as_hex(b []byte, i int) int {
+	bi := b[i]
+	if bi >= 'A' && bi <= 'F' {
+		return int(bi) - 'A' + 10
+	}
+	if bi >= 'a' && bi <= 'f' {
+		return int(bi) - 'a' + 10
+	}
+	return int(bi) - '0'
+}
+
+// Check if the character is ASCII.
+func is_ascii(b []byte, i int) bool {
+	return b[i] <= 0x7F
+}
+
+// Check if the character at the start of the buffer can be printed unescaped.
+func is_printable(b []byte, i int) bool {
+	return ((b[i] == 0x0A) || // . == #x0A
+		(b[i] >= 0x20 && b[i] <= 0x7E) || // #x20 <= . <= #x7E
+		(b[i] == 0xC2 && b[i+1] >= 0xA0) || // #0xA0 <= . <= #xD7FF
+		(b[i] > 0xC2 && b[i] < 0xED) ||
+		(b[i] == 0xED && b[i+1] < 0xA0) ||
+		(b[i] == 0xEE) ||
+		(b[i] == 0xEF && // #xE000 <= . <= #xFFFD
+			!(b[i+1] == 0xBB && b[i+2] == 0xBF) && // && . != #xFEFF
+			!(b[i+1] == 0xBF && (b[i+2] == 0xBE || b[i+2] == 0xBF))))
+}
+
+// Check if the character at the specified position is NUL.
+func is_z(b []byte, i int) bool {
+	return b[i] == 0x00
+}
+
+// Check if the beginning of the buffer is a BOM.
+func is_bom(b []byte, i int) bool {
+	return b[0] == 0xEF && b[1] == 0xBB && b[2] == 0xBF
+}
+
+// Check if the character at the specified position is space.
+func is_space(b []byte, i int) bool {
+	return b[i] == ' '
+}
+
+// Check if the character at the specified position is tab.
+func is_tab(b []byte, i int) bool {
+	return b[i] == '\t'
+}
+
+// Check if the character at the specified position is blank (space or tab).
+func is_blank(b []byte, i int) bool {
+	//return is_space(b, i) || is_tab(b, i)
+	return b[i] == ' ' || b[i] == '\t'
+}
+
+// Check if the character at the specified position is a line break.
+func is_break(b []byte, i int) bool {
+	return (b[i] == '\r' || // CR (#xD)
+		b[i] == '\n' || // LF (#xA)
+		b[i] == 0xC2 && b[i+1] == 0x85 || // NEL (#x85)
+		b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA8 || // LS (#x2028)
+		b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA9) // PS (#x2029)
+}
+
+func is_crlf(b []byte, i int) bool {
+	return b[i] == '\r' && b[i+1] == '\n'
+}
+
+// Check if the character is a line break or NUL.
+func is_breakz(b []byte, i int) bool {
+	//return is_break(b, i) || is_z(b, i)
+	return (        // is_break:
+	b[i] == '\r' || // CR (#xD)
+		b[i] == '\n' || // LF (#xA)
+		b[i] == 0xC2 && b[i+1] == 0x85 || // NEL (#x85)
+		b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA8 || // LS (#x2028)
+		b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA9 || // PS (#x2029)
+		// is_z:
+		b[i] == 0)
+}
+
+// Check if the character is a line break, space, or NUL.
+func is_spacez(b []byte, i int) bool {
+	//return is_space(b, i) || is_breakz(b, i)
+	return ( // is_space:
+	b[i] == ' ' ||
+		// is_breakz:
+		b[i] == '\r' || // CR (#xD)
+		b[i] == '\n' || // LF (#xA)
+		b[i] == 0xC2 && b[i+1] == 0x85 || // NEL (#x85)
+		b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA8 || // LS (#x2028)
+		b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA9 || // PS (#x2029)
+		b[i] == 0)
+}
+
+// Check if the character is a line break, space, tab, or NUL.
+func is_blankz(b []byte, i int) bool {
+	//return is_blank(b, i) || is_breakz(b, i)
+	return ( // is_blank:
+	b[i] == ' ' || b[i] == '\t' ||
+		// is_breakz:
+		b[i] == '\r' || // CR (#xD)
+		b[i] == '\n' || // LF (#xA)
+		b[i] == 0xC2 && b[i+1] == 0x85 || // NEL (#x85)
+		b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA8 || // LS (#x2028)
+		b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA9 || // PS (#x2029)
+		b[i] == 0)
+}
+
+// Determine the width of the character.
+func width(b byte) int {
+	// Don't replace these by a switch without first
+	// confirming that it is being inlined.
+	if b&0x80 == 0x00 {
+		return 1
+	}
+	if b&0xE0 == 0xC0 {
+		return 2
+	}
+	if b&0xF0 == 0xE0 {
+		return 3
+	}
+	if b&0xF8 == 0xF0 {
+		return 4
+	}
+	return 0
+
+}