Add RuboCop and Helix project config

lib/card.rb

@@ -18,16 +18,15 @@ class Card
       @value.to_i
     else
       case @value
-      when "ace"
+      when 'ace'
         11
-      when "jack"
+      when 'jack'
         12
-      when "queen"
+      when 'queen'
         13
-      when "king"
+      when 'king'
         14
       end
     end
   end
 end
-