title: UITableViewAutomaticDimension not working on iOS 8
body: <p>I was following this <a href="http://www.appcoda.com/self-sizing-cells/" rel="noreferrer">tutorial</a> to make self sizing cells.</p>
  
  <p>I registered custom cell into table view and in the cell xib I gave every subview constraints manually. Please refer to the <a href="https://github.com/ztwei/SelfSizingCell" rel="noreferrer">source code in GitHub</a> </p>
  
  <p>Arranging 3 labels vertically in one cell's content view worked fine in iOS 9 but not in iOS 8 (both tested in device and simulator).</p>
  
  <p>In iOS 8 one cell does not have fitting height and not every label shows all it's full text.</p>
  
  <p>iOS 8 not fitting:</p>
  
  <p><a href="https://i.stack.imgur.com/fj20Z.png" rel="noreferrer"><img src="https://i.stack.imgur.com/fj20Z.png" alt="enter image description here"></a></p>
  
  <p>iOS 9 as I expected:</p>
  
  <p><a href="https://i.stack.imgur.com/y2ItI.png" rel="noreferrer"><img src="https://i.stack.imgur.com/y2ItI.png" alt="enter image description here"></a></p>
  
  <p>Any advice would be appreciated!</p>
  
  <p><strong>Update</strong></p>
  
  <p>code in <code>viewDidLoad</code>:</p>
  
  <pre><code> tableView.registerNib(UINib.init(nibName: "SelfSizingCell", bundle: nil), forCellReuseIdentifier: cellIdentifier)
   tableView.dataSource = self
   tableView.delegate = self
   tableView.estimatedRowHeight = 60.0
   tableView.rowHeight = UITableViewAutomaticDimension
   tableView.reloadData()
  </code></pre>