Added Game#over? method

lib/tic_tac_toe/game.rb

@@ -31,6 +31,10 @@ def in_progress?
       !winner? && !tie?
     end
 
+    def over?
+      board.over?
+    end
+
     def winner?
       board.winner?
     end

spec/board_spec.rb

@@ -23,6 +23,12 @@ module TicTacToe
         board.set_cell(1, 'X')
         expect(board.get_cell(1)).to eq 'X'
       end
+
+      it "can remove a cell value" do
+        board.set_cell(1, 'X')
+        board.remove_mark(1)
+        expect(board.get_cell(1)).to eq nil
+      end
     end
 
     describe "#empty_cell?" do

spec/game_spec.rb

@@ -57,6 +57,20 @@ module TicTacToe
       end
     end
 
+    describe "#over?" do
+      it "is false when in play" do
+        expect(game_in_play.over?).to eq false
+      end
+
+      it "is true when won" do
+        expect(won_game.over?).to eq true
+      end
+
+      it "is true when tied" do
+        expect(tie_game.over?).to eq true
+      end
+    end
+
     describe "#winner?" do
       it "is false when in play" do
         expect(game_in_play.winner?).to eq false