title: UICollectionView spacing margins not taking the space from the methods
body: <p>I am trying to kill the margin left that the <code>UICollectionViewCell</code> have as shown in the picture. I tried using all the methods that I could think of to take that margin away but nothing seems to work. All the methods are being called as I tested it with the <code>NSLog</code></p>
  
  <p>What do I have to do so that all the cells are cluster together with no space between them?</p>
  
  <p><img src="https://i.stack.imgur.com/e1wTM.png" alt=""></p>
  
  <pre><code>    - (NSInteger)collectionView:(UICollectionView *)view numberOfItemsInSection:(NSInteger)section {
  
      return 9;
  }
  
  - (NSInteger)numberOfSectionsInCollectionView: (UICollectionView *)collectionView {
      return 1;
  }
  - (CGSize)collectionView:(UICollectionView *)collectionView
                    layout:(UICollectionViewLayout *)collectionViewLayout
    sizeForItemAtIndexPath:(NSIndexPath *)indexPath
  {
      return CGSizeMake(100.f, 67.f);
  }
  - (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {
      NSLog(@"layout1");
      return 0.0f;
  }
  - (UIEdgeInsets)collectionView:(UICollectionView*)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
      NSLog(@"layout2");
      return UIEdgeInsetsMake(0, 0, 0, 0);
  }
  
  - (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {
      NSLog(@"layout3");
      return 0.0f;
  }
  </code></pre>