Delete leftover stuff
Improve command/query exercises
Tweak command query exercise
Add wallet exercise
Tweak appointment test
Add exploration of shovel method
Add shovel bug problem
Add reading list bug problem
Add shovel/hash defaults exploration
Tweak << on fixnum
Improve shovel tests
Improve test helper
Reorder command-query exercises
Update shovel to include shift right on Fixnum and Date
Add checkerboard test
add rudimentary times test
Add blank method
Rename method in money test
add more command-query exercises
Merge pull request #9 from LouisaBarrett/new-exercises

add more command-query exercises