diff --git a/vendor/google.golang.org/protobuf/encoding/protojson/encode.go b/vendor/google.golang.org/protobuf/encoding/protojson/encode.go
new file mode 100644
index 0000000..e545feb
--- /dev/null
+++ b/vendor/google.golang.org/protobuf/encoding/protojson/encode.go
@@ -0,0 +1,394 @@
+// Copyright 2019 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 protojson
+
+import (
+	"encoding/base64"
+	"fmt"
+	"sort"
+
+	"google.golang.org/protobuf/internal/encoding/json"
+	"google.golang.org/protobuf/internal/encoding/messageset"
+	"google.golang.org/protobuf/internal/errors"
+	"google.golang.org/protobuf/internal/flags"
+	"google.golang.org/protobuf/internal/pragma"
+	"google.golang.org/protobuf/proto"
+	pref "google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/reflect/protoregistry"
+)
+
+const defaultIndent = "  "
+
+// Format formats the message as a multiline string.
+// This function is only intended for human consumption and ignores errors.
+// Do not depend on the output being stable. It may change over time across
+// different versions of the program.
+func Format(m proto.Message) string {
+	return MarshalOptions{Multiline: true}.Format(m)
+}
+
+// Marshal writes the given proto.Message in JSON format using default options.
+// Do not depend on the output being stable. It may change over time across
+// different versions of the program.
+func Marshal(m proto.Message) ([]byte, error) {
+	return MarshalOptions{}.Marshal(m)
+}
+
+// MarshalOptions is a configurable JSON format marshaler.
+type MarshalOptions struct {
+	pragma.NoUnkeyedLiterals
+
+	// Multiline specifies whether the marshaler should format the output in
+	// indented-form with every textual element on a new line.
+	// If Indent is an empty string, then an arbitrary indent is chosen.
+	Multiline bool
+
+	// Indent specifies the set of indentation characters to use in a multiline
+	// formatted output such that every entry is preceded by Indent and
+	// terminated by a newline. If non-empty, then Multiline is treated as true.
+	// Indent can only be composed of space or tab characters.
+	Indent string
+
+	// AllowPartial allows messages that have missing required fields to marshal
+	// without returning an error. If AllowPartial is false (the default),
+	// Marshal will return error if there are any missing required fields.
+	AllowPartial bool
+
+	// UseProtoNames uses proto field name instead of lowerCamelCase name in JSON
+	// field names.
+	UseProtoNames bool
+
+	// UseEnumNumbers emits enum values as numbers.
+	UseEnumNumbers bool
+
+	// EmitUnpopulated specifies whether to emit unpopulated fields. It does not
+	// emit unpopulated oneof fields or unpopulated extension fields.
+	// The JSON value emitted for unpopulated fields are as follows:
+	//  ╔═══════╤════════════════════════════╗
+	//  ║ JSON  │ Protobuf field             ║
+	//  ╠═══════╪════════════════════════════╣
+	//  ║ false │ proto3 boolean fields      ║
+	//  ║ 0     │ proto3 numeric fields      ║
+	//  ║ ""    │ proto3 string/bytes fields ║
+	//  ║ null  │ proto2 scalar fields       ║
+	//  ║ null  │ message fields             ║
+	//  ║ []    │ list fields                ║
+	//  ║ {}    │ map fields                 ║
+	//  ╚═══════╧════════════════════════════╝
+	EmitUnpopulated bool
+
+	// Resolver is used for looking up types when expanding google.protobuf.Any
+	// messages. If nil, this defaults to using protoregistry.GlobalTypes.
+	Resolver interface {
+		protoregistry.ExtensionTypeResolver
+		protoregistry.MessageTypeResolver
+	}
+}
+
+// Format formats the message as a string.
+// This method is only intended for human consumption and ignores errors.
+// Do not depend on the output being stable. It may change over time across
+// different versions of the program.
+func (o MarshalOptions) Format(m proto.Message) string {
+	if m == nil || !m.ProtoReflect().IsValid() {
+		return "<nil>" // invalid syntax, but okay since this is for debugging
+	}
+	o.AllowPartial = true
+	b, _ := o.Marshal(m)
+	return string(b)
+}
+
+// Marshal marshals the given proto.Message in the JSON format using options in
+// MarshalOptions. Do not depend on the output being stable. It may change over
+// time across different versions of the program.
+func (o MarshalOptions) Marshal(m proto.Message) ([]byte, error) {
+	if o.Multiline && o.Indent == "" {
+		o.Indent = defaultIndent
+	}
+	if o.Resolver == nil {
+		o.Resolver = protoregistry.GlobalTypes
+	}
+
+	internalEnc, err := json.NewEncoder(o.Indent)
+	if err != nil {
+		return nil, err
+	}
+
+	// Treat nil message interface as an empty message,
+	// in which case the output in an empty JSON object.
+	if m == nil {
+		return []byte("{}"), nil
+	}
+
+	enc := encoder{internalEnc, o}
+	if err := enc.marshalMessage(m.ProtoReflect()); err != nil {
+		return nil, err
+	}
+	if o.AllowPartial {
+		return enc.Bytes(), nil
+	}
+	return enc.Bytes(), proto.CheckInitialized(m)
+}
+
+type encoder struct {
+	*json.Encoder
+	opts MarshalOptions
+}
+
+// marshalMessage marshals the given protoreflect.Message.
+func (e encoder) marshalMessage(m pref.Message) error {
+	if isCustomType(m.Descriptor().FullName()) {
+		return e.marshalCustomType(m)
+	}
+
+	e.StartObject()
+	defer e.EndObject()
+	if err := e.marshalFields(m); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// marshalFields marshals the fields in the given protoreflect.Message.
+func (e encoder) marshalFields(m pref.Message) error {
+	messageDesc := m.Descriptor()
+	if !flags.ProtoLegacy && messageset.IsMessageSet(messageDesc) {
+		return errors.New("no support for proto1 MessageSets")
+	}
+
+	// Marshal out known fields.
+	fieldDescs := messageDesc.Fields()
+	for i := 0; i < fieldDescs.Len(); {
+		fd := fieldDescs.Get(i)
+		if od := fd.ContainingOneof(); od != nil {
+			fd = m.WhichOneof(od)
+			i += od.Fields().Len()
+			if fd == nil {
+				continue // unpopulated oneofs are not affected by EmitUnpopulated
+			}
+		} else {
+			i++
+		}
+
+		val := m.Get(fd)
+		if !m.Has(fd) {
+			if !e.opts.EmitUnpopulated {
+				continue
+			}
+			isProto2Scalar := fd.Syntax() == pref.Proto2 && fd.Default().IsValid()
+			isSingularMessage := fd.Cardinality() != pref.Repeated && fd.Message() != nil
+			if isProto2Scalar || isSingularMessage {
+				// Use invalid value to emit null.
+				val = pref.Value{}
+			}
+		}
+
+		name := fd.JSONName()
+		if e.opts.UseProtoNames {
+			name = string(fd.Name())
+			// Use type name for group field name.
+			if fd.Kind() == pref.GroupKind {
+				name = string(fd.Message().Name())
+			}
+		}
+		if err := e.WriteName(name); err != nil {
+			return err
+		}
+		if err := e.marshalValue(val, fd); err != nil {
+			return err
+		}
+	}
+
+	// Marshal out extensions.
+	if err := e.marshalExtensions(m); err != nil {
+		return err
+	}
+	return nil
+}
+
+// marshalValue marshals the given protoreflect.Value.
+func (e encoder) marshalValue(val pref.Value, fd pref.FieldDescriptor) error {
+	switch {
+	case fd.IsList():
+		return e.marshalList(val.List(), fd)
+	case fd.IsMap():
+		return e.marshalMap(val.Map(), fd)
+	default:
+		return e.marshalSingular(val, fd)
+	}
+}
+
+// marshalSingular marshals the given non-repeated field value. This includes
+// all scalar types, enums, messages, and groups.
+func (e encoder) marshalSingular(val pref.Value, fd pref.FieldDescriptor) error {
+	if !val.IsValid() {
+		e.WriteNull()
+		return nil
+	}
+
+	switch kind := fd.Kind(); kind {
+	case pref.BoolKind:
+		e.WriteBool(val.Bool())
+
+	case pref.StringKind:
+		if e.WriteString(val.String()) != nil {
+			return errors.InvalidUTF8(string(fd.FullName()))
+		}
+
+	case pref.Int32Kind, pref.Sint32Kind, pref.Sfixed32Kind:
+		e.WriteInt(val.Int())
+
+	case pref.Uint32Kind, pref.Fixed32Kind:
+		e.WriteUint(val.Uint())
+
+	case pref.Int64Kind, pref.Sint64Kind, pref.Uint64Kind,
+		pref.Sfixed64Kind, pref.Fixed64Kind:
+		// 64-bit integers are written out as JSON string.
+		e.WriteString(val.String())
+
+	case pref.FloatKind:
+		// Encoder.WriteFloat handles the special numbers NaN and infinites.
+		e.WriteFloat(val.Float(), 32)
+
+	case pref.DoubleKind:
+		// Encoder.WriteFloat handles the special numbers NaN and infinites.
+		e.WriteFloat(val.Float(), 64)
+
+	case pref.BytesKind:
+		e.WriteString(base64.StdEncoding.EncodeToString(val.Bytes()))
+
+	case pref.EnumKind:
+		if fd.Enum().FullName() == "google.protobuf.NullValue" {
+			e.WriteNull()
+		} else {
+			desc := fd.Enum().Values().ByNumber(val.Enum())
+			if e.opts.UseEnumNumbers || desc == nil {
+				e.WriteInt(int64(val.Enum()))
+			} else {
+				e.WriteString(string(desc.Name()))
+			}
+		}
+
+	case pref.MessageKind, pref.GroupKind:
+		if err := e.marshalMessage(val.Message()); err != nil {
+			return err
+		}
+
+	default:
+		panic(fmt.Sprintf("%v has unknown kind: %v", fd.FullName(), kind))
+	}
+	return nil
+}
+
+// marshalList marshals the given protoreflect.List.
+func (e encoder) marshalList(list pref.List, fd pref.FieldDescriptor) error {
+	e.StartArray()
+	defer e.EndArray()
+
+	for i := 0; i < list.Len(); i++ {
+		item := list.Get(i)
+		if err := e.marshalSingular(item, fd); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+type mapEntry struct {
+	key   pref.MapKey
+	value pref.Value
+}
+
+// marshalMap marshals given protoreflect.Map.
+func (e encoder) marshalMap(mmap pref.Map, fd pref.FieldDescriptor) error {
+	e.StartObject()
+	defer e.EndObject()
+
+	// Get a sorted list based on keyType first.
+	entries := make([]mapEntry, 0, mmap.Len())
+	mmap.Range(func(key pref.MapKey, val pref.Value) bool {
+		entries = append(entries, mapEntry{key: key, value: val})
+		return true
+	})
+	sortMap(fd.MapKey().Kind(), entries)
+
+	// Write out sorted list.
+	for _, entry := range entries {
+		if err := e.WriteName(entry.key.String()); err != nil {
+			return err
+		}
+		if err := e.marshalSingular(entry.value, fd.MapValue()); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// sortMap orders list based on value of key field for deterministic ordering.
+func sortMap(keyKind pref.Kind, values []mapEntry) {
+	sort.Slice(values, func(i, j int) bool {
+		switch keyKind {
+		case pref.Int32Kind, pref.Sint32Kind, pref.Sfixed32Kind,
+			pref.Int64Kind, pref.Sint64Kind, pref.Sfixed64Kind:
+			return values[i].key.Int() < values[j].key.Int()
+
+		case pref.Uint32Kind, pref.Fixed32Kind,
+			pref.Uint64Kind, pref.Fixed64Kind:
+			return values[i].key.Uint() < values[j].key.Uint()
+		}
+		return values[i].key.String() < values[j].key.String()
+	})
+}
+
+// marshalExtensions marshals extension fields.
+func (e encoder) marshalExtensions(m pref.Message) error {
+	type entry struct {
+		key   string
+		value pref.Value
+		desc  pref.FieldDescriptor
+	}
+
+	// Get a sorted list based on field key first.
+	var entries []entry
+	m.Range(func(fd pref.FieldDescriptor, v pref.Value) bool {
+		if !fd.IsExtension() {
+			return true
+		}
+
+		// For MessageSet extensions, the name used is the parent message.
+		name := fd.FullName()
+		if messageset.IsMessageSetExtension(fd) {
+			name = name.Parent()
+		}
+
+		// Use [name] format for JSON field name.
+		entries = append(entries, entry{
+			key:   string(name),
+			value: v,
+			desc:  fd,
+		})
+		return true
+	})
+
+	// Sort extensions lexicographically.
+	sort.Slice(entries, func(i, j int) bool {
+		return entries[i].key < entries[j].key
+	})
+
+	// Write out sorted list.
+	for _, entry := range entries {
+		// JSON field name is the proto field name enclosed in [], similar to
+		// textproto. This is consistent with Go v1 lib. C++ lib v3.7.0 does not
+		// marshal out extension fields.
+		if err := e.WriteName("[" + entry.key + "]"); err != nil {
+			return err
+		}
+		if err := e.marshalValue(entry.value, entry.desc); err != nil {
+			return err
+		}
+	}
+	return nil
+}