bump extension to 2.2.1

lighthouse-extension/app/manifest.json

@@ -1,6 +1,6 @@
 {
   "name": "__MSG_appName__",
-  "version": "2.2.0",
+  "version": "2.2.1",
   "minimum_chrome_version": "56",
   "manifest_version": 2,
   "description": "__MSG_appDescription__",