The rails assertion that underlies the `route_matcher` matcher has
changed in Rails 4 to depend on the `message` method from MiniTest.
RSpec is smart enough to make that method available, but only for
controller and routing specs (and only in 2.13.1+).
I marked the `route_matcher` specs as controller specs and updated the
rspec-rails gem development dependency to 2.13.1 or later (but less than 3).
Rails 4 includes strong parameters and removed attr_accessible
(protected attributes). I removed the strong_parameters development
dependency and added it to all non-4.0 appraisals. I also added the
'protected_attributes' gem to the 4.0 appraisal because the test suite
examples make heavy use of attr_accessible.