title: how to play track from certain position using spotify apps API
body: <p>I am developing spotify third party application using javascript API.
  I am trying to play the track from certain position.
  I am having following code,</p>
  
  <p><strong>player.position = 50000;
  player.play(track);</strong></p>
  
  <p>But this code plays track from begining.
  I want to play the track from certain position.
  Is there any way to play track from certain position?
  Thanks.</p>