title: How to get accessToken for firebase 3 using javascript
body: <p>I need to make a shallow rest call using javascript with firebases REST Api, in the past version I needed to pass the access token like this: </p>
  
  <pre><code>    var authKey = ref.getAuth().token;
      var s = firebaseUrl + '/.json?shallow=true&amp;auth=' + authKey;
      $http.get(s)
  </code></pre>
  
  <p>How do I do this now with firebase 3?</p>