Fixes controller pattern matching, add test coverage

:information_desk_person: The existing pattern matching for controllers misses `application_controller.rb`. These changes update the relevant regular expressions to match those used elsewhere (i.e. L61-2). 

I've also added tests for the remaining pattern matching methods. :lipstick: 
I see, changing the doc string to something along the lines of `it "finds model specs when they change"` should suffice.