Drop specs

As first step to have proper tests let's drop broken tests.
Create files rspec needs to work
Add factory_girl_rails gem

It will let us create model instances easily (for testing).
First spec
Track code coverage with simplecov gem
Make users to groups relation many-to-many

Some data will be lost in the process (that users subscribed to some
groups). This shouldn't be a problem (since we are only testing now).
Use many-to-many twix users and questions
Remove fixtures

They are hard to maintain. Let's use Factory Girl to populate database.
Let users subscribe many question categories
Fix all assigned questions page

And add a feature to automatically find out if it breaks in the future
updat db/schema.rb
Merge branch 'master' of github.com:gentoo/recruiting.gentoo.org