Default `rake` to `rake test`

The previous default was `rake parallel_tests`.

Parallel are awesome, but are failing on master right now (could be setup related, I don't know).

In any case, I'm not against parallel_tests, I'm just proposing that they not be the default.
update .gitignore with new RVM file names
Fix mass-assignment error caused by Devise 3.0.0

See plataformatec/devise#2515 for more information
update Travis to test Rails 3.2.14
add favicon support