vendor oci image-spec

Signed-off-by: Mike Brown <brownwm@us.ibm.com>

vendor/github.com/opencontainers/image-spec/specs-go/v1/layout.go

@@ -0,0 +1,28 @@
+// Copyright 2016 The Linux Foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v1
+
+const (
+	// ImageLayoutFile is the file name of oci image layout file
+	ImageLayoutFile = "oci-layout"
+	// ImageLayoutVersion is the version of ImageLayout
+	ImageLayoutVersion = "1.0.0"
+)
+
+// ImageLayout is the structure in the "oci-layout" file, found in the root
+// of an OCI Image-layout directory.
+type ImageLayout struct {
+	Version string `json:"imageLayoutVersion"`
+}