title: UICollectionViewCell Spacing is set to 0 but still have spacing
body: <p>I am trying to make the spacing between my cells = 0</p>
  
  <p>Example of desired result:</p>
  
  <p><img src="https://i.stack.imgur.com/mlRQN.png" alt="enter image description here"></p>
  
  <p>What I currently have (iPhone 6):</p>
  
  <p><img src="https://i.stack.imgur.com/l5fsM.png" alt="enter image description here"></p>
  
  <p>My code:</p>
  
  <pre><code>- (UICollectionViewFlowLayout *)setCollectionViewFlowLayout
  {
      UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
  
      //iphone5 100
      //iphone6 118
      layout.itemSize             = CGSizeMake(118, 118);
      layout.footerReferenceSize  = CGSizeMake(0, 0);
  
      layout.sectionInset            = UIEdgeInsetsMake(0, 0, 0, 0);
      layout.minimumInteritemSpacing = 0.0;
      layout.minimumLineSpacing      = 0.0;
  
      return layout;
  }
  
  - (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section
  {
      return UIEdgeInsetsMake(0, 0, 0, 0);
  }
  </code></pre>
  
  <p>What I have on IB:</p>
  
  <p><img src="https://i.stack.imgur.com/0JM6d.png" alt="enter image description here"></p>
  
  <p>What am I missing? Thanks in advance!</p>