refine tenant api

Signed-off-by: hongming <talonwan@yunify.com>

vendor/gopkg.in/igm/sockjs-go.v2/sockjs/frame.go

@@ -0,0 +1,11 @@
+package sockjs
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+func closeFrame(status uint32, reason string) string {
+	bytes, _ := json.Marshal([]interface{}{status, reason})
+	return fmt.Sprintf("c%s", string(bytes))
+}