added uno deck integrity check

lib/cardshark/deck.rb

@@ -3,5 +3,9 @@ module Deck
     def size
       @cards.size
     end
+
+    def cards
+      @cards
+    end
   end
 end

spec/uno_deck_spec.rb

@@ -9,4 +9,19 @@
   it 'should contain 108 cards' do
     @uno.size.should == 108
   end
+
+  it 'should contain one zero in each suit' do
+    zeros = Hash.new
+    Cardshark::UnoDeck::SUITS.each do |suit|
+      zeros[suit] = 0
+    end
+    @uno.cards.each do |card|
+      if card.rank == :zero then
+        zeros[card.suit] += 1 
+      end
+    end
+    Cardshark::UnoDeck::SUITS.each do |suit|
+      zeros[suit].should == 1
+    end
+  end
 end