setting all categories to be secured led to a blank screen on all pages
use stabby lambda for consistency in class
make the test a little more concise
- move the local assignments into let blocks for
reusability
- remove calls to `to_a`, which aren't needed
- use 'be_empty' instead of '[]' to be consistent
with the other matchers in the test
add a test for the `secured` scope with multiple
secured categories
dadb7eaa23