title: Design a view with corner border swift 3
body: <p>I am new to ios development.I want to design a view which has only corner border rounded as shown in image.</p>
  
  <p>UIView for qrcode scanner:</p>
  
  <p><a href="https://i.stack.imgur.com/3cwpt.png" rel="nofollow noreferrer">desired output</a></p>
  
  <p>I can add border to UIView but i need only white border for view as shown in given image. </p>