Sure, we can make this an argument instead of part of an options hash. The only reason I had done it via options was to be able to make it act like a named argument of sorts. I feel like
`controller_class = controller_for_resource_with_strong_parameters(action: :create)` reads more clearly than `controller_for_resource_with_strong_parameters(:create)`. It was also part of the example you provided - https://github.com/thoughtbot/shoulda-matchers/pull/407#discussion_r9829848

Correct me if I'm wrong, but we cannot use named arguments here since on Travis we'll be testing Ruby 1.9.2 which doesn't support named arguments. Thoughts?