config_service: Add authentication to the UI.

appengine/config_service/ui/bower.json

 {
   "name": "Config UI",
   "description": "This is a UI for the configuration service",
   "main": "index.html",
   "dependencies": {
     "polymer": "Polymer/polymer#^2.0.0",
     "app-layout": "PolymerElements/app-layout",
     "paper-search": "Collaborne/paper-search",
     "google-signin": "GoogleWebComponents/google-signin",
     "iron-ajax": "PolymerElements/iron-ajax",
     "paper-item": "^2.0.0",
     "paper-icon-button": "^2.0.0",
     "iron-icon": "^2.0.0",
     "app-route": "PolymerElements/app-route#^2.0.0"
   },
   "devDependencies": {
     "web-component-tester": "Polymer/web-component-tester#^6.0.0",
     "webcomponentsjs": "webcomponents/webcomponentsjs#^1.0.0"
   },
   "resolutions": {
     "polymer": "^2.0.0",
     "iron-flex-layout": "^2.0.0",
     "webcomponentsjs": "^1.0.0",
-    "iron-icon": "^2.0.0"
+    "iron-icon": "^2.0.0",
+    "iron-a11y-keys-behavior": "1 - 2",

[Sergey Berezin, 2017/06/29 23:52:54]

Let's resolve this and the one below to more specific versions (check which ones
your bower actually installed).

+    "paper-ripple": "1 - 2"
   }
 }