Code coverage
RED draw_{1,2,3}?
GREEN draw_{1,2,3}?
RED draw_{1,2,3}? should return true
GREEN draw_{1,2,3}? should return true
RED draw_{1,2,3}? should return false
GREEN draw_{1,2,3}? should return false
RED always start with 15 sticks
GREEN always start with 15 sticks
REFACTOR to_s code