Update vendor

vendor/github.com/theupdateframework/notary/tuf/data/serializer.go

@@ -0,0 +1,36 @@
+package data
+
+import "github.com/docker/go/canonical/json"
+
+// Serializer is an interface that can marshal and unmarshal TUF data.  This
+// is expected to be a canonical JSON marshaller
+type serializer interface {
+	MarshalCanonical(from interface{}) ([]byte, error)
+	Marshal(from interface{}) ([]byte, error)
+	Unmarshal(from []byte, to interface{}) error
+}
+
+// CanonicalJSON marshals to and from canonical JSON
+type canonicalJSON struct{}
+
+// MarshalCanonical returns the canonical JSON form of a thing
+func (c canonicalJSON) MarshalCanonical(from interface{}) ([]byte, error) {
+	return json.MarshalCanonical(from)
+}
+
+// Marshal returns the regular non-canonical JSON form of a thing
+func (c canonicalJSON) Marshal(from interface{}) ([]byte, error) {
+	return json.Marshal(from)
+}
+
+// Unmarshal unmarshals some JSON bytes
+func (c canonicalJSON) Unmarshal(from []byte, to interface{}) error {
+	return json.Unmarshal(from, to)
+}
+
+// defaultSerializer is a canonical JSON serializer
+var defaultSerializer serializer = canonicalJSON{}
+
+func setDefaultSerializer(s serializer) {
+	defaultSerializer = s
+}