vendor.conf: pin branches to releases or commits

Most of the dependencies have been copied from libpod's vendor.conf
where such a cleanup has been executed recently.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

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

@@ -54,11 +54,6 @@ 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
@@ -78,21 +73,6 @@ func (o WithTagOption) Apply(m ManifestService) error {
 	return nil
 }
 
-// WithManifestMediaTypes lists the media types the client wishes
-// the server to provide.
-func WithManifestMediaTypes(mediaTypes []string) ManifestServiceOption {
-	return WithManifestMediaTypesOption{mediaTypes}
-}
-
-// WithManifestMediaTypesOption holds a list of accepted media types
-type WithManifestMediaTypesOption struct{ MediaTypes []string }
-
-// Apply conforms to the ManifestServiceOption interface
-func (o WithManifestMediaTypesOption) Apply(m ManifestService) error {
-	// no implementation
-	return nil
-}
-
 // Repository is a named collection of manifests and layers.
 type Repository interface {
 	// Named returns the name of the repository.