title: Left Align Cells in UICollectionView
body: <p>I am using a UICollectionView in my project, where there are multiple cells of differing widths on a line. According to:
  <a href="https://developer.apple.com/library/content/documentation/WindowsViews/Conceptual/CollectionViewPGforIOS/UsingtheFlowLayout/UsingtheFlowLayout.html" rel="noreferrer">https://developer.apple.com/library/content/documentation/WindowsViews/Conceptual/CollectionViewPGforIOS/UsingtheFlowLayout/UsingtheFlowLayout.html</a></p>
  
  <p>it spreads the cells out across the line with equal padding. This happens as expected, except I want to left justify them, and hard code a padding width.</p>
  
  <p>I figure I need to subclass UICollectionViewFlowLayout, however after reading some of the tutorials etc online I just don't seem to get how this works.</p>