A few thoughts

Heya Steve,

Code looks pretty good.  Not much to say on that aspect of it.

A few changes in this Pull Request (PR):

*  Declare your version of ruby in Gemfile to avoid inconsistencies across environments
*  Use simplecov gem (https://github.com/colszowka/simplecov) for test coverage metrics
    * Run "bundle exec rspec" and then check out /coverage/index.html.
*  Use .gitignore to exclude autogenerated /coverage directory from git commits.  You don't need it littering up your repository.