diff --git a/vendor/google.golang.org/protobuf/proto/decode.go b/vendor/google.golang.org/protobuf/proto/decode.go
new file mode 100644
index 0000000..4974b16
--- /dev/null
+++ b/vendor/google.golang.org/protobuf/proto/decode.go
@@ -0,0 +1,273 @@
+// Copyright 2018 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 proto
+
+import (
+	"google.golang.org/protobuf/encoding/protowire"
+	"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/reflect/protoreflect"
+	"google.golang.org/protobuf/reflect/protoregistry"
+	"google.golang.org/protobuf/runtime/protoiface"
+)
+
+// UnmarshalOptions configures the unmarshaler.
+//
+// Example usage:
+//   err := UnmarshalOptions{DiscardUnknown: true}.Unmarshal(b, m)
+type UnmarshalOptions struct {
+	pragma.NoUnkeyedLiterals
+
+	// Merge merges the input into the destination message.
+	// The default behavior is to always reset the message before unmarshaling,
+	// unless Merge is specified.
+	Merge bool
+
+	// AllowPartial accepts input for messages that will result in missing
+	// required fields. If AllowPartial is false (the default), Unmarshal will
+	// return an error if there are any missing required fields.
+	AllowPartial bool
+
+	// If DiscardUnknown is set, unknown fields are ignored.
+	DiscardUnknown bool
+
+	// Resolver is used for looking up types when unmarshaling extension fields.
+	// If nil, this defaults to using protoregistry.GlobalTypes.
+	Resolver interface {
+		FindExtensionByName(field protoreflect.FullName) (protoreflect.ExtensionType, error)
+		FindExtensionByNumber(message protoreflect.FullName, field protoreflect.FieldNumber) (protoreflect.ExtensionType, error)
+	}
+}
+
+// Unmarshal parses the wire-format message in b and places the result in m.
+func Unmarshal(b []byte, m Message) error {
+	_, err := UnmarshalOptions{}.unmarshal(b, m.ProtoReflect())
+	return err
+}
+
+// Unmarshal parses the wire-format message in b and places the result in m.
+func (o UnmarshalOptions) Unmarshal(b []byte, m Message) error {
+	_, err := o.unmarshal(b, m.ProtoReflect())
+	return err
+}
+
+// UnmarshalState parses a wire-format message and places the result in m.
+//
+// This method permits fine-grained control over the unmarshaler.
+// Most users should use Unmarshal instead.
+func (o UnmarshalOptions) UnmarshalState(in protoiface.UnmarshalInput) (protoiface.UnmarshalOutput, error) {
+	return o.unmarshal(in.Buf, in.Message)
+}
+
+// unmarshal is a centralized function that all unmarshal operations go through.
+// For profiling purposes, avoid changing the name of this function or
+// introducing other code paths for unmarshal that do not go through this.
+func (o UnmarshalOptions) unmarshal(b []byte, m protoreflect.Message) (out protoiface.UnmarshalOutput, err error) {
+	if o.Resolver == nil {
+		o.Resolver = protoregistry.GlobalTypes
+	}
+	if !o.Merge {
+		Reset(m.Interface())
+	}
+	allowPartial := o.AllowPartial
+	o.Merge = true
+	o.AllowPartial = true
+	methods := protoMethods(m)
+	if methods != nil && methods.Unmarshal != nil &&
+		!(o.DiscardUnknown && methods.Flags&protoiface.SupportUnmarshalDiscardUnknown == 0) {
+		in := protoiface.UnmarshalInput{
+			Message:  m,
+			Buf:      b,
+			Resolver: o.Resolver,
+		}
+		if o.DiscardUnknown {
+			in.Flags |= protoiface.UnmarshalDiscardUnknown
+		}
+		out, err = methods.Unmarshal(in)
+	} else {
+		err = o.unmarshalMessageSlow(b, m)
+	}
+	if err != nil {
+		return out, err
+	}
+	if allowPartial || (out.Flags&protoiface.UnmarshalInitialized != 0) {
+		return out, nil
+	}
+	return out, checkInitialized(m)
+}
+
+func (o UnmarshalOptions) unmarshalMessage(b []byte, m protoreflect.Message) error {
+	_, err := o.unmarshal(b, m)
+	return err
+}
+
+func (o UnmarshalOptions) unmarshalMessageSlow(b []byte, m protoreflect.Message) error {
+	md := m.Descriptor()
+	if messageset.IsMessageSet(md) {
+		return o.unmarshalMessageSet(b, m)
+	}
+	fields := md.Fields()
+	for len(b) > 0 {
+		// Parse the tag (field number and wire type).
+		num, wtyp, tagLen := protowire.ConsumeTag(b)
+		if tagLen < 0 {
+			return protowire.ParseError(tagLen)
+		}
+		if num > protowire.MaxValidNumber {
+			return errors.New("invalid field number")
+		}
+
+		// Find the field descriptor for this field number.
+		fd := fields.ByNumber(num)
+		if fd == nil && md.ExtensionRanges().Has(num) {
+			extType, err := o.Resolver.FindExtensionByNumber(md.FullName(), num)
+			if err != nil && err != protoregistry.NotFound {
+				return errors.New("%v: unable to resolve extension %v: %v", md.FullName(), num, err)
+			}
+			if extType != nil {
+				fd = extType.TypeDescriptor()
+			}
+		}
+		var err error
+		if fd == nil {
+			err = errUnknown
+		} else if flags.ProtoLegacy {
+			if fd.IsWeak() && fd.Message().IsPlaceholder() {
+				err = errUnknown // weak referent is not linked in
+			}
+		}
+
+		// Parse the field value.
+		var valLen int
+		switch {
+		case err != nil:
+		case fd.IsList():
+			valLen, err = o.unmarshalList(b[tagLen:], wtyp, m.Mutable(fd).List(), fd)
+		case fd.IsMap():
+			valLen, err = o.unmarshalMap(b[tagLen:], wtyp, m.Mutable(fd).Map(), fd)
+		default:
+			valLen, err = o.unmarshalSingular(b[tagLen:], wtyp, m, fd)
+		}
+		if err != nil {
+			if err != errUnknown {
+				return err
+			}
+			valLen = protowire.ConsumeFieldValue(num, wtyp, b[tagLen:])
+			if valLen < 0 {
+				return protowire.ParseError(valLen)
+			}
+			if !o.DiscardUnknown {
+				m.SetUnknown(append(m.GetUnknown(), b[:tagLen+valLen]...))
+			}
+		}
+		b = b[tagLen+valLen:]
+	}
+	return nil
+}
+
+func (o UnmarshalOptions) unmarshalSingular(b []byte, wtyp protowire.Type, m protoreflect.Message, fd protoreflect.FieldDescriptor) (n int, err error) {
+	v, n, err := o.unmarshalScalar(b, wtyp, fd)
+	if err != nil {
+		return 0, err
+	}
+	switch fd.Kind() {
+	case protoreflect.GroupKind, protoreflect.MessageKind:
+		m2 := m.Mutable(fd).Message()
+		if err := o.unmarshalMessage(v.Bytes(), m2); err != nil {
+			return n, err
+		}
+	default:
+		// Non-message scalars replace the previous value.
+		m.Set(fd, v)
+	}
+	return n, nil
+}
+
+func (o UnmarshalOptions) unmarshalMap(b []byte, wtyp protowire.Type, mapv protoreflect.Map, fd protoreflect.FieldDescriptor) (n int, err error) {
+	if wtyp != protowire.BytesType {
+		return 0, errUnknown
+	}
+	b, n = protowire.ConsumeBytes(b)
+	if n < 0 {
+		return 0, protowire.ParseError(n)
+	}
+	var (
+		keyField = fd.MapKey()
+		valField = fd.MapValue()
+		key      protoreflect.Value
+		val      protoreflect.Value
+		haveKey  bool
+		haveVal  bool
+	)
+	switch valField.Kind() {
+	case protoreflect.GroupKind, protoreflect.MessageKind:
+		val = mapv.NewValue()
+	}
+	// Map entries are represented as a two-element message with fields
+	// containing the key and value.
+	for len(b) > 0 {
+		num, wtyp, n := protowire.ConsumeTag(b)
+		if n < 0 {
+			return 0, protowire.ParseError(n)
+		}
+		if num > protowire.MaxValidNumber {
+			return 0, errors.New("invalid field number")
+		}
+		b = b[n:]
+		err = errUnknown
+		switch num {
+		case 1:
+			key, n, err = o.unmarshalScalar(b, wtyp, keyField)
+			if err != nil {
+				break
+			}
+			haveKey = true
+		case 2:
+			var v protoreflect.Value
+			v, n, err = o.unmarshalScalar(b, wtyp, valField)
+			if err != nil {
+				break
+			}
+			switch valField.Kind() {
+			case protoreflect.GroupKind, protoreflect.MessageKind:
+				if err := o.unmarshalMessage(v.Bytes(), val.Message()); err != nil {
+					return 0, err
+				}
+			default:
+				val = v
+			}
+			haveVal = true
+		}
+		if err == errUnknown {
+			n = protowire.ConsumeFieldValue(num, wtyp, b)
+			if n < 0 {
+				return 0, protowire.ParseError(n)
+			}
+		} else if err != nil {
+			return 0, err
+		}
+		b = b[n:]
+	}
+	// Every map entry should have entries for key and value, but this is not strictly required.
+	if !haveKey {
+		key = keyField.Default()
+	}
+	if !haveVal {
+		switch valField.Kind() {
+		case protoreflect.GroupKind, protoreflect.MessageKind:
+		default:
+			val = valField.Default()
+		}
+	}
+	mapv.Set(key.MapKey(), val)
+	return n, nil
+}
+
+// errUnknown is used internally to indicate fields which should be added
+// to the unknown field set of a message. It is never returned from an exported
+// function.
+var errUnknown = errors.New("BUG: internal error (unknown)")