title: Deselect all other selections if one cell selected from other section in UICollectionView
body: <p>How to deselect all other selected cells in UICollectionView in section 0 if any cell selected from section 1.<br>
  Below is what i tried so far:</p>
  
  <pre><code>func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath){
  
      let cell = collectionView.cellForItemAtIndexPath(indexPath) as! SignupStep3CollectionViewCell
  
      cell.layer.borderWidth = 4
      cell.layer.masksToBounds = false
      cell.layer.borderColor = UIColor.init(red: 46.0/255.0, green: 234.0/255.0, blue: 219.0/255.0, alpha: 1.0).CGColor
      cell.layer.cornerRadius = cell.frame.height/2
      cell.clipsToBounds = true
  
      if indexPath.section == 1
      {
          collectionView.selectItemAtIndexPath(nil, animated: true, scrollPosition: .None)
      }
  }
  </code></pre>
  
  <p>this is not working please guide.</p>