remove RPS from exercises
add a basic stubbing example
First exercise
Second exercise
Third exercise
Fourth exercise
Fifth exercise
Sixth exercise
Seventh exercise
Seventh exercise, with nil array handler
Eighth exercise
Ninth exercise
Tenth exercise
Eleventh exercise
Eleventh exercise, with exercise 9 changed to working print rather than put
Eleventh exercise, with time stubbing for 11th exercise
Eleventh exercise, with the exercise time cleaned up
Extension, first attempt (ugly)
Extension, hash swapping
Extension, hash swapping, alternate build