Move deps from _workspace/ to vendor/

godep restore
pushd $GOPATH/src/github.com/appc/spec
git co master
popd
go get go4.org/errorutil
rm -rf Godeps
godep save ./...
git add vendor
git add -f $(git ls-files --other vendor/)
git co -- Godeps/LICENSES Godeps/.license_file_state Godeps/OWNERS

vendor/github.com/docker/engine-api/client/image_history.go

@@ -0,0 +1,22 @@
+package client
+
+import (
+	"encoding/json"
+	"net/url"
+
+	"github.com/docker/engine-api/types"
+	"golang.org/x/net/context"
+)
+
+// ImageHistory returns the changes in an image in history format.
+func (cli *Client) ImageHistory(ctx context.Context, imageID string) ([]types.ImageHistory, error) {
+	var history []types.ImageHistory
+	serverResp, err := cli.get(ctx, "/images/"+imageID+"/history", url.Values{}, nil)
+	if err != nil {
+		return history, err
+	}
+
+	err = json.NewDecoder(serverResp.body).Decode(&history)
+	ensureReaderClosed(serverResp)
+	return history, err
+}