Run (make vendor)

Temporarily vendor opencontainers/image-spec from a fork
to fix "id" value duplication, which is detected and
refused by gojsonschema now
( https://github.com/opencontainers/image-spec/pull/750 ).

Signed-off-by: Miloslav Trmač <mitr@redhat.com>

vendor/github.com/docker/distribution/registry.go

@@ -54,6 +54,11 @@ type RepositoryEnumerator interface {
 	Enumerate(ctx context.Context, ingester func(string) error) error
 }
 
+// RepositoryRemover removes given repository
+type RepositoryRemover interface {
+	Remove(ctx context.Context, name reference.Named) error
+}
+
 // ManifestServiceOption is a function argument for Manifest Service methods
 type ManifestServiceOption interface {
 	Apply(ManifestService) error