vendor: include github.com/opencontainers/image-spec

Signed-off-by: Stephen J Day <stephen.day@docker.com>

vendor/github.com/opencontainers/image-spec/specs-go/version.go

@@ -0,0 +1,32 @@
+// 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 specs
+
+import "fmt"
+
+const (
+	// VersionMajor is for an API incompatible changes
+	VersionMajor = 1
+	// VersionMinor is for functionality in a backwards-compatible manner
+	VersionMinor = 0
+	// VersionPatch is for backwards-compatible bug fixes
+	VersionPatch = 0
+
+	// VersionDev indicates development branch. Releases will be empty string.
+	VersionDev = "-rc3-dev"
+)
+
+// Version is the specification version that the package types support.
+var Version = fmt.Sprintf("%d.%d.%d%s", VersionMajor, VersionMinor, VersionPatch, VersionDev)