Fix issue in PHP versions < 5.5 (again)
Pre-release
      Pre-release
    
        Merge pull request #16 from caxy/feature-list_diffing-new Missed an array_column in ListDiff. Updated to use ArrayColumn function.
Merge pull request #16 from caxy/feature-list_diffing-new Missed an array_column in ListDiff. Updated to use ArrayColumn function.