Test were failing because this line were doing (at the end):
`self.class.to_s.downcase`

If we have an ActiveRecord --> `ThingInteresting`
This give us something like that: `thinginteresting`

And then in this line
https://github.com/teambox/permalink_fu/blob/master/lib/permalink_fu.rb#L34

We do that:
`klass.classify.constantize`
And fail! test broken.