RSpec it out yo.
* New spec rake task
* Added tests for ::generate and ::valid? methods
Merge pull request #1 from drfeelngood/rspec

RSpec it out yo.
I RSpec the input and the moves.
Refactored methods and added documentation.
* Implemented Yardoc
* New rake yard task
* Removed the 'action' parameter for caclulating check digits
Merge pull request #2 from drfeelngood/block

Refactored methods and added documentation.