title: Rails association - how to add the 'has_many' object to the 'owner'
body: <p>In my app, a <code>user</code> has many <code>score_cards</code> and a <code>score_card</code> belongs to a <code>user</code></p>
  
  <p>The question is, whenever I create a new <code>score_card</code>, ie, <code>ScoreCardsController.create</code> gets called, how do I add this newly created <code>score_card</code> to the <code>current_user</code> (I'm using devise, so <code>current_user</code> is a valid <code>User</code> object).</p>