Don't require action_controller/test_case

[Aesthetikx]

This was initially introduced in 738074f in order to allow draper to work in a rails console session, however this no longer seems necessary.

Requiring this file in non test environments has the consequence of breaking ActionController::Live as discussed in rails issue 31200.

[Aesthetikx]

Actually, I had not tested this with a decorator using the h helper, and indeed, this does seem to be a required require. Furthermore, this code is only used during rails console and rails runner, so it is not hit during a rails server, unless you have spring running and use a rails console, so this is not as much of a problem as I originally thought, so I am closing this PR.