Updated CDN link
Moved code from answers controller into answer instance methods. Added tests for answer model.
Fixed bug in US comparison. Added rank order to answer show country_list. Fixed answer feedback based on rank order.
Moved answer prompt word into answer instance method
Moved creation of bias points into class method on BiasPoint
Correct answer_spec test for get_rank_order
Moved selection of valid countries into Criterion instance method
Moved retreival of criterion scores and valid countries from answers#show into models.
Merged branch refactors and resolved conflict