Update Battleship!

Makes the battleship length 2 instead of 1.  Need to update game for hitting/sinking battleship of length 2.
As written, code is positioning of battleship is biased toward edges.  Should re-write as such:
1. randomly determine whether positioning will be vertical or horizontal.
2. if vertical, randomly assign rand_col a value between and including 1 and 5.
3. set rand_col2 = rand_col1.
4. randomly assign rand_row to a value between 1 and 4.
5. set rand_row2 = rand_row1+1
6. write similar code for if horizontal.

this code will be more parsimonious and unbiased.