title: UITableViewController refreshControl is glitchy when UITableViewController frame.height is small
body: <p>I have a problem that stems from the fact that UITableViewController refreshControl is glitchy when the frame of the UITableViewController is below a certain height.</p>
  
  <p>As it stands, I have a UIViewController, and in it I have a ContainerView that embeds a UITableViewController. I want the height to be 50% of the screen. </p>
  
  <p>When I use the refreshControl, I get this kind of behavior: <a href="http://streamable.com/8suq" rel="noreferrer">The tableView jumps down at the very end when scrolling down. You'll notice it towards the end of this video when I decide to scroll down slowly.</a></p>
  
  <p>This problem does not occur when the ContainerView frame is above a certain value. So, when the height is 75% of the screen, everything works perfectly and the refreshControl is smooth. When it is 50%, then that bug happens.</p>
  
  <p>Two different things I have tried:</p>
  
  <ol>
  <li><p><code>self.tableView.frame = CGRectMake(0, numOfPixelsToDropTableBy, self.tableView.frame.size.width, self.tableView.frame.size.height)</code> is one thing that I tried. The problem with this is if you want to give the tableView rounded corners via the ContainerView and the fact that your ContainerView still takes up more space and this makes constraints for other elements awkward.</p></li>
  <li><p>I went to the Storyboard and I basically had the top of the ContainerView where I wanted. Then, I had the bottom extend beyond the bottom of the screen to give the ContainerView a large enough height... but the user would never know. Except, they would know because now the tableView extends beyond the screen and I can't see the last few rows of my tableView.</p></li>
  </ol>
  
  <p>Ultimately... I don't want to use a 3rd-party library, but I want a perfectly functioning refreshControl. How can I fix this?</p>