Rotate Array
	
	/**
	 * Given an array and an integer k. Rotate the array around k in place.
	 * 
	 * e.g. 
	 * 
	 * 		{1, 2, 3, 4, 5}		k = 3
	 * 
	 * 		{4, 5, 1, 2, 3}
	 * 
	 * */