adds test to ensure results getter fails after payoffs_list deletion
adds test to ensure results getter fails after payoffs_list deletion

mojones/Axelrod,uglyfruitcake/Axelrod,bootandy/Axelrod,mojones/Axelrod,risicle/Axelrod,uglyfruitcake/Axelrod,kathryncrouch/Axelrod,emmagordon/Axelrod,risicle/Axelrod,emmagordon/Axelrod,bootandy/Axelrod,kathryncrouch/Axelrod