ITP1 - Assignment: Tic Tac Toe

Brandon Conway (TA)

You are REALLY close to having a working solution in the return branch.
The only thing you need to do is break if there is a winner as well as
if the choices array is empty.

change line 52:

break if choices.empty?

to:

break if winner || choices.empty?

This works because you are returning either a string or nil from the
for_the_win method.