code: function shuffleArray(array){
      var length = array.length;
      var randomIndex;
      var currentIndex = 0;
      var tmp;
      for (; currentIndex < length; currentIndex++) {
          randomIndex = Math.floor(Math.random() * length);
          tmp = array[currentIndex];
          array[currentIndex] = array[randomIndex];
          array[randomIndex] = tmp;
      }
      return array;
  }
docs: Shuffles items in an array
  Operation takes O(n) time. The array passed is operated on as its
  reference, rather than value, is passed to the function.
  
  @public
  
  @param {Array} array - an array of items
  @return {Array} array with the the items shuffled