Should have instance variable @player which holds and object of the Player class.
@player needs to be accessible for writing. => attr_writer
Should have instance variable @board that is accessible with attr_reader.
@board should be initialized as a new board each round in the initialize method.
Should have a method called place_ships that randomly chooses where the computers ships will go and places them on the @board object using the @board.place(...) method
Should have a method called fire which randomly (or smartly for Iteration 4) fires at a player's board using @player.board.cells[coordinate].fire_upon method. Should not fire on cells which are already fired_upon?. Should also puts a string to the terminal that says "My shot on #{coordinate} was a hit/miss"
Should have a method called all_ships_sunk? which returns true if all the ships on @board are sunk. May be helpful to create an instance variable for the computer that holds an array of the ships on the board so we can easily iterate through them with @ships.all?{ |ship| ship.sunk? }. Currently ships are only stored by the individual cells.