Refactor and update the docs for XO::Grid
Refactor and update the docs for XO::Evaluator
Refactor and update the docs for XO::Engine
Refactor and update the docs for XO::AI::GeometricGrid
Refactor XO::AI::Minimax
Refactor a bit more and update the docs for XO::AI::Minimax
Add a test to ensure that the correct moves, non in this case, are returned when the game is over
Add a bit more to the docs for XO::AI::Minimax
Update the README