title: Navigation Bar Not Showing after Adding NavigationController
body: <p>I have an existing <code>UITableViewController</code> that I've embedded in a <code>NavigationController</code>. However, the Navigation Bar is not showing when I present the view.</p>
  
  <p>Presenting the <code>TableViewController</code> (its Storyboard id is: <code>SelectServicesController</code>) :</p>
  
  <pre><code>if let selectServicesController = self.storyboard?.instantiateViewControllerWithIdentifier("SelectServicesController") as? UITableViewController {
      self.navigationController?.presentViewController(selectServicesController, animated: true, completion: nil)
  }
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/S1G49.png" rel="noreferrer"><img src="https://i.stack.imgur.com/S1G49.png" alt="enter image description here"></a></p>
  
  <p>This is what it looks like when I build (nav bar does not show):</p>
  
  <p><a href="https://i.stack.imgur.com/Bi3pQ.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Bi3pQ.png" alt="enter image description here"></a></p>