Flesh out the game loop

* Use a new, currently empty `Board#winner?` method as our loop
  condition
* Add `Player#insignia` so we can print the correct player insignia
  depending on who the current player is
* Print the board and a prompt for coordinates
* Switch the current player after a player finishes moving

1 files changed, 3 insertions, 0 deletions

diff --git a/spec/board_spec.rb b/spec/board_spec.rb
index ae1bdd0..09f50e1 100644
--- a/spec/board_spec.rb
+++ b/spec/board_spec.rb
@@ -57,4 +57,7 @@ EOF
       @board.instance_variable_get(:@board)[1][2].must_equal value
     end
   end
+  
+  describe '#winner?' do
+  end
 end