add coverall service
add gems-status to Gemfile

First step to run gems-status
(http://github.com/jordimassaguerpla/gems-status) and collect the data in the database
add Gemfile files for testing and populate the database with their path

These Gemfiles will be used for testing the import of data from
gems-status
add Gemfile.lock (I missed that file in the previous commit)
add a rake task that runs the gems-status and ...

inserts into the database the information for the gems. There is no
checks yet but that will be implemented after.
add the native checker and refactor gems_status:run rake task