Add glide.yaml and vendor deps

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

@@ -0,0 +1,28 @@
+package client
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/url"
+
+	"github.com/docker/engine-api/types"
+	"golang.org/x/net/context"
+)
+
+// RegistryLogin authenticates the docker server with a given docker registry.
+// It returns UnauthorizerError when the authentication fails.
+func (cli *Client) RegistryLogin(ctx context.Context, auth types.AuthConfig) (types.AuthResponse, error) {
+	resp, err := cli.post(ctx, "/auth", url.Values{}, auth, nil)
+
+	if resp.statusCode == http.StatusUnauthorized {
+		return types.AuthResponse{}, unauthorizedError{err}
+	}
+	if err != nil {
+		return types.AuthResponse{}, err
+	}
+
+	var response types.AuthResponse
+	err = json.NewDecoder(resp.body).Decode(&response)
+	ensureReaderClosed(resp)
+	return response, err
+}