title: How to center a UICollectionView when it is tapped?
body: <p>I have a <code>UICollectionView</code> and it has quite a lot of <code>UICollectionViewCells</code> on it. I want to scroll the cell to the centre of the <code>UICollectionView</code> when it is tapped. My concern is that even if I tap the last or the top cell it should move to the centre of the collection view.</p>
  
  <p>I have tried setting the <code>contentInsets</code> and offsets but they don't seem to work. I think I will have to change the content size on selection and change it back to original when the scrolling begins.</p>