For this coding challenge you'll build a simplified version of battleship. You'll have 3 ships that will be placed on a 10 by 10 grid which is the battleground. Each cell in the battleground is identified by its space on an x,y axis with [0,0] being the cell in the bottom left corner. Each ship is 1 cell wide and 3 cells long. On initial placement, each ship is oriented vertically. To initialize the playing field you'll receive a 2 dimensional array where each element in the array contains the x,y coordinates of each ship's topmost cell. Your game interface will be a basic HTTP API. You should assume that you are implementing a spec that has already been published to clients and they will use the spec to learn how to interact with the game. We want you to flesh out the provided BattleshipsController so that the create action accepts a 2-dimensional array (represented as a string) that contains the topmost cell coordinates of ships to initialize the playing board.