title: UISearchBar scrolls while the UITableView is scrolling
body: <p>How to accomplish the <code>UISearchBar</code> scrolling effect like Instagram.app? The <code>UISearchBar</code> is scrolling up while the <code>UITableView</code> is scrolling up. The <code>UISearchBar</code> stop scroll down when it's origin.y equals to 0;
   <img src="https://i.stack.imgur.com/dQ2qF.jpg" alt="enter image description here"></p>
  
  <p><img src="https://i.stack.imgur.com/mo5t8.jpg" alt="enter image description here"></p>