diff --git a/vendor/github.com/gogo/protobuf/proto/extensions_gogo.go b/vendor/github.com/gogo/protobuf/proto/extensions_gogo.go
new file mode 100644
index 0000000..53ebd8c
--- /dev/null
+++ b/vendor/github.com/gogo/protobuf/proto/extensions_gogo.go
@@ -0,0 +1,368 @@
+// Protocol Buffers for Go with Gadgets
+//
+// Copyright (c) 2013, The GoGo Authors. All rights reserved.
+// http://github.com/gogo/protobuf
+//
+// 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.
+//
+// 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.
+
+package proto
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"reflect"
+	"sort"
+	"strings"
+	"sync"
+)
+
+type extensionsBytes interface {
+	Message
+	ExtensionRangeArray() []ExtensionRange
+	GetExtensions() *[]byte
+}
+
+type slowExtensionAdapter struct {
+	extensionsBytes
+}
+
+func (s slowExtensionAdapter) extensionsWrite() map[int32]Extension {
+	panic("Please report a bug to github.com/gogo/protobuf if you see this message: Writing extensions is not supported for extensions stored in a byte slice field.")
+}
+
+func (s slowExtensionAdapter) extensionsRead() (map[int32]Extension, sync.Locker) {
+	b := s.GetExtensions()
+	m, err := BytesToExtensionsMap(*b)
+	if err != nil {
+		panic(err)
+	}
+	return m, notLocker{}
+}
+
+func GetBoolExtension(pb Message, extension *ExtensionDesc, ifnotset bool) bool {
+	if reflect.ValueOf(pb).IsNil() {
+		return ifnotset
+	}
+	value, err := GetExtension(pb, extension)
+	if err != nil {
+		return ifnotset
+	}
+	if value == nil {
+		return ifnotset
+	}
+	if value.(*bool) == nil {
+		return ifnotset
+	}
+	return *(value.(*bool))
+}
+
+func (this *Extension) Equal(that *Extension) bool {
+	if err := this.Encode(); err != nil {
+		return false
+	}
+	if err := that.Encode(); err != nil {
+		return false
+	}
+	return bytes.Equal(this.enc, that.enc)
+}
+
+func (this *Extension) Compare(that *Extension) int {
+	if err := this.Encode(); err != nil {
+		return 1
+	}
+	if err := that.Encode(); err != nil {
+		return -1
+	}
+	return bytes.Compare(this.enc, that.enc)
+}
+
+func SizeOfInternalExtension(m extendableProto) (n int) {
+	info := getMarshalInfo(reflect.TypeOf(m))
+	return info.sizeV1Extensions(m.extensionsWrite())
+}
+
+type sortableMapElem struct {
+	field int32
+	ext   Extension
+}
+
+func newSortableExtensionsFromMap(m map[int32]Extension) sortableExtensions {
+	s := make(sortableExtensions, 0, len(m))
+	for k, v := range m {
+		s = append(s, &sortableMapElem{field: k, ext: v})
+	}
+	return s
+}
+
+type sortableExtensions []*sortableMapElem
+
+func (this sortableExtensions) Len() int { return len(this) }
+
+func (this sortableExtensions) Swap(i, j int) { this[i], this[j] = this[j], this[i] }
+
+func (this sortableExtensions) Less(i, j int) bool { return this[i].field < this[j].field }
+
+func (this sortableExtensions) String() string {
+	sort.Sort(this)
+	ss := make([]string, len(this))
+	for i := range this {
+		ss[i] = fmt.Sprintf("%d: %v", this[i].field, this[i].ext)
+	}
+	return "map[" + strings.Join(ss, ",") + "]"
+}
+
+func StringFromInternalExtension(m extendableProto) string {
+	return StringFromExtensionsMap(m.extensionsWrite())
+}
+
+func StringFromExtensionsMap(m map[int32]Extension) string {
+	return newSortableExtensionsFromMap(m).String()
+}
+
+func StringFromExtensionsBytes(ext []byte) string {
+	m, err := BytesToExtensionsMap(ext)
+	if err != nil {
+		panic(err)
+	}
+	return StringFromExtensionsMap(m)
+}
+
+func EncodeInternalExtension(m extendableProto, data []byte) (n int, err error) {
+	return EncodeExtensionMap(m.extensionsWrite(), data)
+}
+
+func EncodeExtensionMap(m map[int32]Extension, data []byte) (n int, err error) {
+	o := 0
+	for _, e := range m {
+		if err := e.Encode(); err != nil {
+			return 0, err
+		}
+		n := copy(data[o:], e.enc)
+		if n != len(e.enc) {
+			return 0, io.ErrShortBuffer
+		}
+		o += n
+	}
+	return o, nil
+}
+
+func GetRawExtension(m map[int32]Extension, id int32) ([]byte, error) {
+	e := m[id]
+	if err := e.Encode(); err != nil {
+		return nil, err
+	}
+	return e.enc, nil
+}
+
+func size(buf []byte, wire int) (int, error) {
+	switch wire {
+	case WireVarint:
+		_, n := DecodeVarint(buf)
+		return n, nil
+	case WireFixed64:
+		return 8, nil
+	case WireBytes:
+		v, n := DecodeVarint(buf)
+		return int(v) + n, nil
+	case WireFixed32:
+		return 4, nil
+	case WireStartGroup:
+		offset := 0
+		for {
+			u, n := DecodeVarint(buf[offset:])
+			fwire := int(u & 0x7)
+			offset += n
+			if fwire == WireEndGroup {
+				return offset, nil
+			}
+			s, err := size(buf[offset:], wire)
+			if err != nil {
+				return 0, err
+			}
+			offset += s
+		}
+	}
+	return 0, fmt.Errorf("proto: can't get size for unknown wire type %d", wire)
+}
+
+func BytesToExtensionsMap(buf []byte) (map[int32]Extension, error) {
+	m := make(map[int32]Extension)
+	i := 0
+	for i < len(buf) {
+		tag, n := DecodeVarint(buf[i:])
+		if n <= 0 {
+			return nil, fmt.Errorf("unable to decode varint")
+		}
+		fieldNum := int32(tag >> 3)
+		wireType := int(tag & 0x7)
+		l, err := size(buf[i+n:], wireType)
+		if err != nil {
+			return nil, err
+		}
+		end := i + int(l) + n
+		m[int32(fieldNum)] = Extension{enc: buf[i:end]}
+		i = end
+	}
+	return m, nil
+}
+
+func NewExtension(e []byte) Extension {
+	ee := Extension{enc: make([]byte, len(e))}
+	copy(ee.enc, e)
+	return ee
+}
+
+func AppendExtension(e Message, tag int32, buf []byte) {
+	if ee, eok := e.(extensionsBytes); eok {
+		ext := ee.GetExtensions()
+		*ext = append(*ext, buf...)
+		return
+	}
+	if ee, eok := e.(extendableProto); eok {
+		m := ee.extensionsWrite()
+		ext := m[int32(tag)] // may be missing
+		ext.enc = append(ext.enc, buf...)
+		m[int32(tag)] = ext
+	}
+}
+
+func encodeExtension(extension *ExtensionDesc, value interface{}) ([]byte, error) {
+	u := getMarshalInfo(reflect.TypeOf(extension.ExtendedType))
+	ei := u.getExtElemInfo(extension)
+	v := value
+	p := toAddrPointer(&v, ei.isptr)
+	siz := ei.sizer(p, SizeVarint(ei.wiretag))
+	buf := make([]byte, 0, siz)
+	return ei.marshaler(buf, p, ei.wiretag, false)
+}
+
+func decodeExtensionFromBytes(extension *ExtensionDesc, buf []byte) (interface{}, error) {
+	o := 0
+	for o < len(buf) {
+		tag, n := DecodeVarint((buf)[o:])
+		fieldNum := int32(tag >> 3)
+		wireType := int(tag & 0x7)
+		if o+n > len(buf) {
+			return nil, fmt.Errorf("unable to decode extension")
+		}
+		l, err := size((buf)[o+n:], wireType)
+		if err != nil {
+			return nil, err
+		}
+		if int32(fieldNum) == extension.Field {
+			if o+n+l > len(buf) {
+				return nil, fmt.Errorf("unable to decode extension")
+			}
+			v, err := decodeExtension((buf)[o:o+n+l], extension)
+			if err != nil {
+				return nil, err
+			}
+			return v, nil
+		}
+		o += n + l
+	}
+	return defaultExtensionValue(extension)
+}
+
+func (this *Extension) Encode() error {
+	if this.enc == nil {
+		var err error
+		this.enc, err = encodeExtension(this.desc, this.value)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (this Extension) GoString() string {
+	if err := this.Encode(); err != nil {
+		return fmt.Sprintf("error encoding extension: %v", err)
+	}
+	return fmt.Sprintf("proto.NewExtension(%#v)", this.enc)
+}
+
+func SetUnsafeExtension(pb Message, fieldNum int32, value interface{}) error {
+	typ := reflect.TypeOf(pb).Elem()
+	ext, ok := extensionMaps[typ]
+	if !ok {
+		return fmt.Errorf("proto: bad extended type; %s is not extendable", typ.String())
+	}
+	desc, ok := ext[fieldNum]
+	if !ok {
+		return errors.New("proto: bad extension number; not in declared ranges")
+	}
+	return SetExtension(pb, desc, value)
+}
+
+func GetUnsafeExtension(pb Message, fieldNum int32) (interface{}, error) {
+	typ := reflect.TypeOf(pb).Elem()
+	ext, ok := extensionMaps[typ]
+	if !ok {
+		return nil, fmt.Errorf("proto: bad extended type; %s is not extendable", typ.String())
+	}
+	desc, ok := ext[fieldNum]
+	if !ok {
+		return nil, fmt.Errorf("unregistered field number %d", fieldNum)
+	}
+	return GetExtension(pb, desc)
+}
+
+func NewUnsafeXXX_InternalExtensions(m map[int32]Extension) XXX_InternalExtensions {
+	x := &XXX_InternalExtensions{
+		p: new(struct {
+			mu           sync.Mutex
+			extensionMap map[int32]Extension
+		}),
+	}
+	x.p.extensionMap = m
+	return *x
+}
+
+func GetUnsafeExtensionsMap(extendable Message) map[int32]Extension {
+	pb := extendable.(extendableProto)
+	return pb.extensionsWrite()
+}
+
+func deleteExtension(pb extensionsBytes, theFieldNum int32, offset int) int {
+	ext := pb.GetExtensions()
+	for offset < len(*ext) {
+		tag, n1 := DecodeVarint((*ext)[offset:])
+		fieldNum := int32(tag >> 3)
+		wireType := int(tag & 0x7)
+		n2, err := size((*ext)[offset+n1:], wireType)
+		if err != nil {
+			panic(err)
+		}
+		newOffset := offset + n1 + n2
+		if fieldNum == theFieldNum {
+			*ext = append((*ext)[:offset], (*ext)[newOffset:]...)
+			return offset
+		}
+		offset = newOffset
+	}
+	return -1
+}