diff --git a/vendor/google.golang.org/protobuf/reflect/protoreflect/value_union.go b/vendor/google.golang.org/protobuf/reflect/protoreflect/value_union.go
new file mode 100644
index 0000000..f334f71
--- /dev/null
+++ b/vendor/google.golang.org/protobuf/reflect/protoreflect/value_union.go
@@ -0,0 +1,409 @@
+// 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 protoreflect
+
+import (
+	"fmt"
+	"math"
+)
+
+// Value is a union where only one Go type may be set at a time.
+// The Value is used to represent all possible values a field may take.
+// The following shows which Go type is used to represent each proto Kind:
+//
+//	╔════════════╤═════════════════════════════════════╗
+//	║ Go type    │ Protobuf kind                       ║
+//	╠════════════╪═════════════════════════════════════╣
+//	║ bool       │ BoolKind                            ║
+//	║ int32      │ Int32Kind, Sint32Kind, Sfixed32Kind ║
+//	║ int64      │ Int64Kind, Sint64Kind, Sfixed64Kind ║
+//	║ uint32     │ Uint32Kind, Fixed32Kind             ║
+//	║ uint64     │ Uint64Kind, Fixed64Kind             ║
+//	║ float32    │ FloatKind                           ║
+//	║ float64    │ DoubleKind                          ║
+//	║ string     │ StringKind                          ║
+//	║ []byte     │ BytesKind                           ║
+//	║ EnumNumber │ EnumKind                            ║
+//	║ Message    │ MessageKind, GroupKind              ║
+//	╚════════════╧═════════════════════════════════════╝
+//
+// Multiple protobuf Kinds may be represented by a single Go type if the type
+// can losslessly represent the information for the proto kind. For example,
+// Int64Kind, Sint64Kind, and Sfixed64Kind are all represented by int64,
+// but use different integer encoding methods.
+//
+// The List or Map types are used if the field cardinality is repeated.
+// A field is a List if FieldDescriptor.IsList reports true.
+// A field is a Map if FieldDescriptor.IsMap reports true.
+//
+// Converting to/from a Value and a concrete Go value panics on type mismatch.
+// For example, ValueOf("hello").Int() panics because this attempts to
+// retrieve an int64 from a string.
+type Value value
+
+// The protoreflect API uses a custom Value union type instead of interface{}
+// to keep the future open for performance optimizations. Using an interface{}
+// always incurs an allocation for primitives (e.g., int64) since it needs to
+// be boxed on the heap (as interfaces can only contain pointers natively).
+// Instead, we represent the Value union as a flat struct that internally keeps
+// track of which type is set. Using unsafe, the Value union can be reduced
+// down to 24B, which is identical in size to a slice.
+//
+// The latest compiler (Go1.11) currently suffers from some limitations:
+//	• With inlining, the compiler should be able to statically prove that
+//	only one of these switch cases are taken and inline one specific case.
+//	See https://golang.org/issue/22310.
+
+// ValueOf returns a Value initialized with the concrete value stored in v.
+// This panics if the type does not match one of the allowed types in the
+// Value union.
+func ValueOf(v interface{}) Value {
+	switch v := v.(type) {
+	case nil:
+		return Value{}
+	case bool:
+		return ValueOfBool(v)
+	case int32:
+		return ValueOfInt32(v)
+	case int64:
+		return ValueOfInt64(v)
+	case uint32:
+		return ValueOfUint32(v)
+	case uint64:
+		return ValueOfUint64(v)
+	case float32:
+		return ValueOfFloat32(v)
+	case float64:
+		return ValueOfFloat64(v)
+	case string:
+		return ValueOfString(v)
+	case []byte:
+		return ValueOfBytes(v)
+	case EnumNumber:
+		return ValueOfEnum(v)
+	case Message, List, Map:
+		return valueOfIface(v)
+	default:
+		panic(fmt.Sprintf("invalid type: %T", v))
+	}
+}
+
+// ValueOfBool returns a new boolean value.
+func ValueOfBool(v bool) Value {
+	if v {
+		return Value{typ: boolType, num: 1}
+	} else {
+		return Value{typ: boolType, num: 0}
+	}
+}
+
+// ValueOfInt32 returns a new int32 value.
+func ValueOfInt32(v int32) Value {
+	return Value{typ: int32Type, num: uint64(v)}
+}
+
+// ValueOfInt64 returns a new int64 value.
+func ValueOfInt64(v int64) Value {
+	return Value{typ: int64Type, num: uint64(v)}
+}
+
+// ValueOfUint32 returns a new uint32 value.
+func ValueOfUint32(v uint32) Value {
+	return Value{typ: uint32Type, num: uint64(v)}
+}
+
+// ValueOfUint64 returns a new uint64 value.
+func ValueOfUint64(v uint64) Value {
+	return Value{typ: uint64Type, num: v}
+}
+
+// ValueOfFloat32 returns a new float32 value.
+func ValueOfFloat32(v float32) Value {
+	return Value{typ: float32Type, num: uint64(math.Float64bits(float64(v)))}
+}
+
+// ValueOfFloat64 returns a new float64 value.
+func ValueOfFloat64(v float64) Value {
+	return Value{typ: float64Type, num: uint64(math.Float64bits(float64(v)))}
+}
+
+// ValueOfString returns a new string value.
+func ValueOfString(v string) Value {
+	return valueOfString(v)
+}
+
+// ValueOfBytes returns a new bytes value.
+func ValueOfBytes(v []byte) Value {
+	return valueOfBytes(v[:len(v):len(v)])
+}
+
+// ValueOfEnum returns a new enum value.
+func ValueOfEnum(v EnumNumber) Value {
+	return Value{typ: enumType, num: uint64(v)}
+}
+
+// ValueOfMessage returns a new Message value.
+func ValueOfMessage(v Message) Value {
+	return valueOfIface(v)
+}
+
+// ValueOfList returns a new List value.
+func ValueOfList(v List) Value {
+	return valueOfIface(v)
+}
+
+// ValueOfMap returns a new Map value.
+func ValueOfMap(v Map) Value {
+	return valueOfIface(v)
+}
+
+// IsValid reports whether v is populated with a value.
+func (v Value) IsValid() bool {
+	return v.typ != nilType
+}
+
+// Interface returns v as an interface{}.
+//
+// Invariant: v == ValueOf(v).Interface()
+func (v Value) Interface() interface{} {
+	switch v.typ {
+	case nilType:
+		return nil
+	case boolType:
+		return v.Bool()
+	case int32Type:
+		return int32(v.Int())
+	case int64Type:
+		return int64(v.Int())
+	case uint32Type:
+		return uint32(v.Uint())
+	case uint64Type:
+		return uint64(v.Uint())
+	case float32Type:
+		return float32(v.Float())
+	case float64Type:
+		return float64(v.Float())
+	case stringType:
+		return v.String()
+	case bytesType:
+		return v.Bytes()
+	case enumType:
+		return v.Enum()
+	default:
+		return v.getIface()
+	}
+}
+
+func (v Value) typeName() string {
+	switch v.typ {
+	case nilType:
+		return "nil"
+	case boolType:
+		return "bool"
+	case int32Type:
+		return "int32"
+	case int64Type:
+		return "int64"
+	case uint32Type:
+		return "uint32"
+	case uint64Type:
+		return "uint64"
+	case float32Type:
+		return "float32"
+	case float64Type:
+		return "float64"
+	case stringType:
+		return "string"
+	case bytesType:
+		return "bytes"
+	case enumType:
+		return "enum"
+	default:
+		switch v := v.getIface().(type) {
+		case Message:
+			return "message"
+		case List:
+			return "list"
+		case Map:
+			return "map"
+		default:
+			return fmt.Sprintf("<unknown: %T>", v)
+		}
+	}
+}
+
+func (v Value) panicMessage(what string) string {
+	return fmt.Sprintf("type mismatch: cannot convert %v to %s", v.typeName(), what)
+}
+
+// Bool returns v as a bool and panics if the type is not a bool.
+func (v Value) Bool() bool {
+	switch v.typ {
+	case boolType:
+		return v.num > 0
+	default:
+		panic(v.panicMessage("bool"))
+	}
+}
+
+// Int returns v as a int64 and panics if the type is not a int32 or int64.
+func (v Value) Int() int64 {
+	switch v.typ {
+	case int32Type, int64Type:
+		return int64(v.num)
+	default:
+		panic(v.panicMessage("int"))
+	}
+}
+
+// Uint returns v as a uint64 and panics if the type is not a uint32 or uint64.
+func (v Value) Uint() uint64 {
+	switch v.typ {
+	case uint32Type, uint64Type:
+		return uint64(v.num)
+	default:
+		panic(v.panicMessage("uint"))
+	}
+}
+
+// Float returns v as a float64 and panics if the type is not a float32 or float64.
+func (v Value) Float() float64 {
+	switch v.typ {
+	case float32Type, float64Type:
+		return math.Float64frombits(uint64(v.num))
+	default:
+		panic(v.panicMessage("float"))
+	}
+}
+
+// String returns v as a string. Since this method implements fmt.Stringer,
+// this returns the formatted string value for any non-string type.
+func (v Value) String() string {
+	switch v.typ {
+	case stringType:
+		return v.getString()
+	default:
+		return fmt.Sprint(v.Interface())
+	}
+}
+
+// Bytes returns v as a []byte and panics if the type is not a []byte.
+func (v Value) Bytes() []byte {
+	switch v.typ {
+	case bytesType:
+		return v.getBytes()
+	default:
+		panic(v.panicMessage("bytes"))
+	}
+}
+
+// Enum returns v as a EnumNumber and panics if the type is not a EnumNumber.
+func (v Value) Enum() EnumNumber {
+	switch v.typ {
+	case enumType:
+		return EnumNumber(v.num)
+	default:
+		panic(v.panicMessage("enum"))
+	}
+}
+
+// Message returns v as a Message and panics if the type is not a Message.
+func (v Value) Message() Message {
+	switch vi := v.getIface().(type) {
+	case Message:
+		return vi
+	default:
+		panic(v.panicMessage("message"))
+	}
+}
+
+// List returns v as a List and panics if the type is not a List.
+func (v Value) List() List {
+	switch vi := v.getIface().(type) {
+	case List:
+		return vi
+	default:
+		panic(v.panicMessage("list"))
+	}
+}
+
+// Map returns v as a Map and panics if the type is not a Map.
+func (v Value) Map() Map {
+	switch vi := v.getIface().(type) {
+	case Map:
+		return vi
+	default:
+		panic(v.panicMessage("map"))
+	}
+}
+
+// MapKey returns v as a MapKey and panics for invalid MapKey types.
+func (v Value) MapKey() MapKey {
+	switch v.typ {
+	case boolType, int32Type, int64Type, uint32Type, uint64Type, stringType:
+		return MapKey(v)
+	default:
+		panic(v.panicMessage("map key"))
+	}
+}
+
+// MapKey is used to index maps, where the Go type of the MapKey must match
+// the specified key Kind (see MessageDescriptor.IsMapEntry).
+// The following shows what Go type is used to represent each proto Kind:
+//
+//	╔═════════╤═════════════════════════════════════╗
+//	║ Go type │ Protobuf kind                       ║
+//	╠═════════╪═════════════════════════════════════╣
+//	║ bool    │ BoolKind                            ║
+//	║ int32   │ Int32Kind, Sint32Kind, Sfixed32Kind ║
+//	║ int64   │ Int64Kind, Sint64Kind, Sfixed64Kind ║
+//	║ uint32  │ Uint32Kind, Fixed32Kind             ║
+//	║ uint64  │ Uint64Kind, Fixed64Kind             ║
+//	║ string  │ StringKind                          ║
+//	╚═════════╧═════════════════════════════════════╝
+//
+// A MapKey is constructed and accessed through a Value:
+//	k := ValueOf("hash").MapKey() // convert string to MapKey
+//	s := k.String()               // convert MapKey to string
+//
+// The MapKey is a strict subset of valid types used in Value;
+// converting a Value to a MapKey with an invalid type panics.
+type MapKey value
+
+// IsValid reports whether k is populated with a value.
+func (k MapKey) IsValid() bool {
+	return Value(k).IsValid()
+}
+
+// Interface returns k as an interface{}.
+func (k MapKey) Interface() interface{} {
+	return Value(k).Interface()
+}
+
+// Bool returns k as a bool and panics if the type is not a bool.
+func (k MapKey) Bool() bool {
+	return Value(k).Bool()
+}
+
+// Int returns k as a int64 and panics if the type is not a int32 or int64.
+func (k MapKey) Int() int64 {
+	return Value(k).Int()
+}
+
+// Uint returns k as a uint64 and panics if the type is not a uint32 or uint64.
+func (k MapKey) Uint() uint64 {
+	return Value(k).Uint()
+}
+
+// String returns k as a string. Since this method implements fmt.Stringer,
+// this returns the formatted string value for any non-string type.
+func (k MapKey) String() string {
+	return Value(k).String()
+}
+
+// Value returns k as a Value.
+func (k MapKey) Value() Value {
+	return Value(k)
+}