diff --git a/vendor/google.golang.org/protobuf/reflect/protoreflect/value.go b/vendor/google.golang.org/protobuf/reflect/protoreflect/value.go
new file mode 100644
index 0000000..f319810
--- /dev/null
+++ b/vendor/google.golang.org/protobuf/reflect/protoreflect/value.go
@@ -0,0 +1,285 @@
+// 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 "google.golang.org/protobuf/encoding/protowire"
+
+// Enum is a reflection interface for a concrete enum value,
+// which provides type information and a getter for the enum number.
+// Enum does not provide a mutable API since enums are commonly backed by
+// Go constants, which are not addressable.
+type Enum interface {
+	// Descriptor returns enum descriptor, which contains only the protobuf
+	// type information for the enum.
+	Descriptor() EnumDescriptor
+
+	// Type returns the enum type, which encapsulates both Go and protobuf
+	// type information. If the Go type information is not needed,
+	// it is recommended that the enum descriptor be used instead.
+	Type() EnumType
+
+	// Number returns the enum value as an integer.
+	Number() EnumNumber
+}
+
+// Message is a reflective interface for a concrete message value,
+// encapsulating both type and value information for the message.
+//
+// Accessor/mutators for individual fields are keyed by FieldDescriptor.
+// For non-extension fields, the descriptor must exactly match the
+// field known by the parent message.
+// For extension fields, the descriptor must implement ExtensionTypeDescriptor,
+// extend the parent message (i.e., have the same message FullName), and
+// be within the parent's extension range.
+//
+// Each field Value can be a scalar or a composite type (Message, List, or Map).
+// See Value for the Go types associated with a FieldDescriptor.
+// Providing a Value that is invalid or of an incorrect type panics.
+type Message interface {
+	// Descriptor returns message descriptor, which contains only the protobuf
+	// type information for the message.
+	Descriptor() MessageDescriptor
+
+	// Type returns the message type, which encapsulates both Go and protobuf
+	// type information. If the Go type information is not needed,
+	// it is recommended that the message descriptor be used instead.
+	Type() MessageType
+
+	// New returns a newly allocated and mutable empty message.
+	New() Message
+
+	// Interface unwraps the message reflection interface and
+	// returns the underlying ProtoMessage interface.
+	Interface() ProtoMessage
+
+	// Range iterates over every populated field in an undefined order,
+	// calling f for each field descriptor and value encountered.
+	// Range returns immediately if f returns false.
+	// While iterating, mutating operations may only be performed
+	// on the current field descriptor.
+	Range(f func(FieldDescriptor, Value) bool)
+
+	// Has reports whether a field is populated.
+	//
+	// Some fields have the property of nullability where it is possible to
+	// distinguish between the default value of a field and whether the field
+	// was explicitly populated with the default value. Singular message fields,
+	// member fields of a oneof, and proto2 scalar fields are nullable. Such
+	// fields are populated only if explicitly set.
+	//
+	// In other cases (aside from the nullable cases above),
+	// a proto3 scalar field is populated if it contains a non-zero value, and
+	// a repeated field is populated if it is non-empty.
+	Has(FieldDescriptor) bool
+
+	// Clear clears the field such that a subsequent Has call reports false.
+	//
+	// Clearing an extension field clears both the extension type and value
+	// associated with the given field number.
+	//
+	// Clear is a mutating operation and unsafe for concurrent use.
+	Clear(FieldDescriptor)
+
+	// Get retrieves the value for a field.
+	//
+	// For unpopulated scalars, it returns the default value, where
+	// the default value of a bytes scalar is guaranteed to be a copy.
+	// For unpopulated composite types, it returns an empty, read-only view
+	// of the value; to obtain a mutable reference, use Mutable.
+	Get(FieldDescriptor) Value
+
+	// Set stores the value for a field.
+	//
+	// For a field belonging to a oneof, it implicitly clears any other field
+	// that may be currently set within the same oneof.
+	// For extension fields, it implicitly stores the provided ExtensionType.
+	// When setting a composite type, it is unspecified whether the stored value
+	// aliases the source's memory in any way. If the composite value is an
+	// empty, read-only value, then it panics.
+	//
+	// Set is a mutating operation and unsafe for concurrent use.
+	Set(FieldDescriptor, Value)
+
+	// Mutable returns a mutable reference to a composite type.
+	//
+	// If the field is unpopulated, it may allocate a composite value.
+	// For a field belonging to a oneof, it implicitly clears any other field
+	// that may be currently set within the same oneof.
+	// For extension fields, it implicitly stores the provided ExtensionType
+	// if not already stored.
+	// It panics if the field does not contain a composite type.
+	//
+	// Mutable is a mutating operation and unsafe for concurrent use.
+	Mutable(FieldDescriptor) Value
+
+	// NewField returns a new value that is assignable to the field
+	// for the given descriptor. For scalars, this returns the default value.
+	// For lists, maps, and messages, this returns a new, empty, mutable value.
+	NewField(FieldDescriptor) Value
+
+	// WhichOneof reports which field within the oneof is populated,
+	// returning nil if none are populated.
+	// It panics if the oneof descriptor does not belong to this message.
+	WhichOneof(OneofDescriptor) FieldDescriptor
+
+	// GetUnknown retrieves the entire list of unknown fields.
+	// The caller may only mutate the contents of the RawFields
+	// if the mutated bytes are stored back into the message with SetUnknown.
+	GetUnknown() RawFields
+
+	// SetUnknown stores an entire list of unknown fields.
+	// The raw fields must be syntactically valid according to the wire format.
+	// An implementation may panic if this is not the case.
+	// Once stored, the caller must not mutate the content of the RawFields.
+	// An empty RawFields may be passed to clear the fields.
+	//
+	// SetUnknown is a mutating operation and unsafe for concurrent use.
+	SetUnknown(RawFields)
+
+	// IsValid reports whether the message is valid.
+	//
+	// An invalid message is an empty, read-only value.
+	//
+	// An invalid message often corresponds to a nil pointer of the concrete
+	// message type, but the details are implementation dependent.
+	// Validity is not part of the protobuf data model, and may not
+	// be preserved in marshaling or other operations.
+	IsValid() bool
+
+	// ProtoMethods returns optional fast-path implementions of various operations.
+	// This method may return nil.
+	//
+	// The returned methods type is identical to
+	// "google.golang.org/protobuf/runtime/protoiface".Methods.
+	// Consult the protoiface package documentation for details.
+	ProtoMethods() *methods
+}
+
+// RawFields is the raw bytes for an ordered sequence of fields.
+// Each field contains both the tag (representing field number and wire type),
+// and also the wire data itself.
+type RawFields []byte
+
+// IsValid reports whether b is syntactically correct wire format.
+func (b RawFields) IsValid() bool {
+	for len(b) > 0 {
+		_, _, n := protowire.ConsumeField(b)
+		if n < 0 {
+			return false
+		}
+		b = b[n:]
+	}
+	return true
+}
+
+// List is a zero-indexed, ordered list.
+// The element Value type is determined by FieldDescriptor.Kind.
+// Providing a Value that is invalid or of an incorrect type panics.
+type List interface {
+	// Len reports the number of entries in the List.
+	// Get, Set, and Truncate panic with out of bound indexes.
+	Len() int
+
+	// Get retrieves the value at the given index.
+	// It never returns an invalid value.
+	Get(int) Value
+
+	// Set stores a value for the given index.
+	// When setting a composite type, it is unspecified whether the set
+	// value aliases the source's memory in any way.
+	//
+	// Set is a mutating operation and unsafe for concurrent use.
+	Set(int, Value)
+
+	// Append appends the provided value to the end of the list.
+	// When appending a composite type, it is unspecified whether the appended
+	// value aliases the source's memory in any way.
+	//
+	// Append is a mutating operation and unsafe for concurrent use.
+	Append(Value)
+
+	// AppendMutable appends a new, empty, mutable message value to the end
+	// of the list and returns it.
+	// It panics if the list does not contain a message type.
+	AppendMutable() Value
+
+	// Truncate truncates the list to a smaller length.
+	//
+	// Truncate is a mutating operation and unsafe for concurrent use.
+	Truncate(int)
+
+	// NewElement returns a new value for a list element.
+	// For enums, this returns the first enum value.
+	// For other scalars, this returns the zero value.
+	// For messages, this returns a new, empty, mutable value.
+	NewElement() Value
+
+	// IsValid reports whether the list is valid.
+	//
+	// An invalid list is an empty, read-only value.
+	//
+	// Validity is not part of the protobuf data model, and may not
+	// be preserved in marshaling or other operations.
+	IsValid() bool
+}
+
+// Map is an unordered, associative map.
+// The entry MapKey type is determined by FieldDescriptor.MapKey.Kind.
+// The entry Value type is determined by FieldDescriptor.MapValue.Kind.
+// Providing a MapKey or Value that is invalid or of an incorrect type panics.
+type Map interface {
+	// Len reports the number of elements in the map.
+	Len() int
+
+	// Range iterates over every map entry in an undefined order,
+	// calling f for each key and value encountered.
+	// Range calls f Len times unless f returns false, which stops iteration.
+	// While iterating, mutating operations may only be performed
+	// on the current map key.
+	Range(f func(MapKey, Value) bool)
+
+	// Has reports whether an entry with the given key is in the map.
+	Has(MapKey) bool
+
+	// Clear clears the entry associated with they given key.
+	// The operation does nothing if there is no entry associated with the key.
+	//
+	// Clear is a mutating operation and unsafe for concurrent use.
+	Clear(MapKey)
+
+	// Get retrieves the value for an entry with the given key.
+	// It returns an invalid value for non-existent entries.
+	Get(MapKey) Value
+
+	// Set stores the value for an entry with the given key.
+	// It panics when given a key or value that is invalid or the wrong type.
+	// When setting a composite type, it is unspecified whether the set
+	// value aliases the source's memory in any way.
+	//
+	// Set is a mutating operation and unsafe for concurrent use.
+	Set(MapKey, Value)
+
+	// Mutable retrieves a mutable reference to the entry for the given key.
+	// If no entry exists for the key, it creates a new, empty, mutable value
+	// and stores it as the entry for the key.
+	// It panics if the map value is not a message.
+	Mutable(MapKey) Value
+
+	// NewValue returns a new value assignable as a map value.
+	// For enums, this returns the first enum value.
+	// For other scalars, this returns the zero value.
+	// For messages, this returns a new, empty, mutable value.
+	NewValue() Value
+
+	// IsValid reports whether the map is valid.
+	//
+	// An invalid map is an empty, read-only value.
+	//
+	// An invalid message often corresponds to a nil Go map value,
+	// but the details are implementation dependent.
+	// Validity is not part of the protobuf data model, and may not
+	// be preserved in marshaling or other operations.
+	IsValid() bool
+}