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, 2 insertions, 0 deletions

diff --git a/player.rb b/player.rb
index 8146220..07301f8 100644
--- a/player.rb
+++ b/player.rb
@@ -4,6 +4,8 @@ class Player
     :o => 'O'
   }
   
+  attr_reader :insignia
+  
   def initialize(insignia, board)
     @insignia = insignia
     @board = board