title: Retrieve data from new Firebase
body: <p>Please help. After migrating to new Firebase I can't retrieve data.
  Use this construction: </p>
  
  <pre><code>let ref = FIRDatabase.database().reference()
  
  override func viewDidLoad() {
      super.viewDidLoad()
      ref.observeEventType(FIRDataEventType.Value, withBlock: { (snapshot) in
          let postDict = snapshot.value as! [String : AnyObject]
          print("\(postDict)")
      })
  }
  </code></pre>
  
  <p>After running I see error:</p>
  
  <pre><code>2016-05-19 10:04:22.264 123a[88652:13688922] The default app has not been configured yet.
  2016-05-19 10:04:22.276 123a[88652:13688922] *** Terminating app due to uncaught exception 'MissingDatabaseURL', reason: 'Failed to get FIRDatabase instance: FIRApp object has no databaseURL in its FirebaseOptions object.'
  *** First throw call stack:
  </code></pre>
  
  <p>I read documentation, but can't resolve this problem.
  GoogleService-Info.plist I add to project.</p>