title: Shadow is not displaying on UIView
body: <p>I have one ViewController and in that controller there are two UIViews.</p>
  
  <p>I want to add at the bottom of first UIView shadow which is shown on this second UIView.</p>
  
  <pre><code>first UIView
  
  -------------
                &lt;- shadow here
  secondUIView
  </code></pre>
  
  <p>But when I simply add this code it's not working.</p>
  
  <pre><code> firstView.layer.masksToBounds = true
   firstView.layer.shadowOffset = CGSizeMake(0,5)
   firstView.layer.shadowOpacity = 0.5
   firstView.layer.shadowPath = UIBezierPath(rect: firstView.bounds).CGPath
  </code></pre>