title: Swift - UIAlertController not showing up anything
body: <p>What have I done wrong? I have tested this on iOS 8.1 simulator and iPod Tocuh 5G with iOS 8.1.</p>
  
  <pre><code>var alert = UIAlertController(title: "Also save this picture?", message: "Adding this picture to your Camera Roll might be a good idea.", preferredStyle: UIAlertControllerStyle.Alert)
              alert.addAction(UIAlertAction(title: "Yes", style: UIAlertActionStyle.Default, handler: { (action: UIAlertAction!) in
                       UIImageWriteToSavedPhotosAlbum(takenImage, nil, nil, nil)
                  }))
              alert.addAction(UIAlertAction(title: "No", style: UIAlertActionStyle.Cancel, handler: nil))
              self.presentViewController(alert, animated: true, completion: nil)
  </code></pre>