code: function removeAtIndex(arr, index) {
      var item = arr[index];
      arr.splice(index, 1);
      return item;
  }
docs: Remove an item from the passed in arr
  from the index.
  @param  {Array} arr
  @param  {Number} index
  @return {Object} the item removed.
  
  var arr = [1,2,3];
  Luc.Array.removeAtIndex(arr, 1);
  >2
  arr;
  >[1,3]