Counting, how does it work?
Removing old difference-of-squares
Palindromes for today
Add extensions, switch spec to tests

Create extension example and extension example tests
Switch from minitest/spec to minitest/unit
Rename bob.rb to classy_example.rb so people know it's an example
Merge pull request #8 from vosechu/bob-solutions

Add extensions, switch spec to tests
merging changes from upstream