title: Cannot read property '_location' of null with Jest on Firebase auth in a create-react-app application
body: <p>I created a new application with create-react-app 0.8.5.<br>
  I want to test firebase authentification with Jest like that :  </p>
  
  <pre><code>import * as firebase from 'firebase';
  describe('Firebase', function() {
      it('auth succeed', () =&gt; {
          const config = {  
              apiKey: "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX",
              authDomain: "XXXXXXXXXXXX.firebaseapp.com",
              databaseURL: "https://XXXXXXXXXXXX.firebaseio.com",
              storageBucket: "XXXXXXXXXXXX.appspot.com",
              messagingSenderId: "YYYYYYYYYYYYYYYY"
          };
          const database = firebase  
              .initializeApp(config)
              .database()
              .ref();
          firebase.auth().signInWithEmailAndPassword("toto@mail.com", "zzzzzz").catch(function(error) {
              fail("Auth error");
          });
      });
  });
  </code></pre>
  
  <p>But i obtain that error :  </p>
  
  <pre><code>TypeError: Cannot read property '_location' of null
      at Window.location (D:\...\node_modules\jsdom\lib\jsdom\browser\Window.js:147:79)
      at callback [as _onTimeout] (D:\...\node_modules\jsdom\lib\jsdom\browser\Window.js:479:40)
      at Timer.listOnTimeout (timers.js:92:15)
   npm ERR! Test failed.  See above for more details.
  </code></pre>
  
  <p>Have you any clue to explain that ?<br>
  Is there any way to have more log on that error ?   </p>