Remove unused types in registry package

Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>

registry/types.go

@@ -33,23 +33,6 @@ type RegistryInfo struct {
 	Standalone bool   `json:"standalone"`
 }
 
-type FSLayer struct {
-	BlobSum string `json:"blobSum"`
-}
-
-type ManifestHistory struct {
-	V1Compatibility string `json:"v1Compatibility"`
-}
-
-type ManifestData struct {
-	Name          string             `json:"name"`
-	Tag           string             `json:"tag"`
-	Architecture  string             `json:"architecture"`
-	FSLayers      []*FSLayer         `json:"fsLayers"`
-	History       []*ManifestHistory `json:"history"`
-	SchemaVersion int                `json:"schemaVersion"`
-}
-
 type APIVersion int
 
 func (av APIVersion) String() string {