We were testing what happens when users disable features in the admin
panel, so it makes sense to test what happens from the user's point of
view when trying to access a disabled feature: they see a page with the
test "Internal server error".
Whether we should responde with 500 Internal server error page or a 404
Not Found is up to debate; personally I find the latter more
appropriate.
Code based on the article "Changing Rails consider_all_requests_local in
RSpec fails" [1].
[1] http://atodorov.org/blog/2016/04/27/changing-rails-consider_all_requests_local-in-rspec-fails/
We were repeating the same code over and over (with a few variants) to
setup tests which require an administrator. We can use a tag and
simplify the code.
