Slight tightening of source, enhancement to tests, and addition of Simplecov to tests

Hi Patricio,

I have added `ruby` / `utf-8` meta comments to the top of each of the ruby files.
I have also added a simple pair of dummy helper methods to the `root_helpers.rb` and `application_helpers.rb` along with enhancements to the tests just to prove that they work.
I have also added `simplecov` reporting to the tests.
Finally I have added a note in the `README` explaining how to run the tests.

Please accept these minor contributions at your pleasure.

Dave