Update the cdn link to use gstatic (#640)

kmcnellis · bojeil-google · commit 749e36d4255b · 2019-10-22T23:52:13.000-07:00
cdn.firebase.com is old - we should be pointing at the new gstatic service
diff --git a/README.md b/README.md
@@ -60,8 +60,8 @@ You just need to include the following script and CSS file in the `<head>` tag
 of your page, below the initialization snippet from the Firebase Console:
 
 ```html
-<script src="https://cdn.firebase.com/libs/firebaseui/4.2.0/firebaseui.js"></script>
-<link type="text/css" rel="stylesheet" href="https://cdn.firebase.com/libs/firebaseui/4.2.0/firebaseui.css" />
+<script src="https://www.gstatic.com/firebasejs/ui/4.2.0/firebase-ui-auth.js"></script>
+<link type="text/css" rel="stylesheet" href="https://www.gstatic.com/firebasejs/ui/4.2.0/firebase-ui-auth.css" />
 ```
 
 #### Localized Widget
