title: Animate Text Change of UILabel
body: <p><strong>I want to animate text changes in a UILabel.</strong> </p>
  
  <p>For example: old text moves up and new text moves in from the bottom.</p>
  
  <p>I already realised that I would need to labels. One for the old and one for the new text. The second <code>UILabel</code> is located below the first. Then both animate up.</p>
  
  <p>However, how do you cut off the first label as it animates past the top portion of the frame?</p>