Add error message for undef
Add runner:hint() and first few hints
Update .gitignore to stop committing answered koans
Finished adding hints.
Add koans for less-than/greater-than
DRY up executable, update readme, improve boolean expression koan
Merge pull request #3 from bentrevor/add-hints

Add hints
Correct last test name in boolean expressions test
Merge pull request #4 from sputnikus/bool-test-fix

Correct last test name in boolean expressions test
Begin building about list comprehensions topic