title: UIBarButtonItem Title Offset
body: <p>I'm trying to use a unicode symbol in a UIBarButtonItem title, but changing the label size makes it too high vertically, and it is obviously off center.</p>
  
  <p><img src="https://i.stack.imgur.com/fLTaq.png" alt="ergh"></p>
  
  <p>Code currently being used:</p>
  
  <pre><code>let fontDict = [NSFontAttributeName: UIFont.systemFontOfSize(30.0)]
  editButton.title = "✎"
  editButton.setTitleTextAttributes(fontDict, forState: UIControlState.Normal)
  </code></pre>
  
  <p>I've tried adding an offset, but it doesn't seem to do anything.</p>
  
  <pre><code>editButton.setTitlePositionAdjustment(UIOffsetMake(0, -10.0), forBarMetrics: UIBarMetrics.Default)
  </code></pre>