:all_after_pass no longer functions in Ubuntu

[neerolyte]

This might be specific to the way notifications are working in Ubuntu.

This change: https://github.com/Maher4Ever/guard-phpunit/commit/66aafde9dc5b3f907dba8ce88be2cb8e87cc68c1

results in run_tests() always returning true, hence :all_after_pass no longer functions.

I had a look through the tests and because $? is stubbed all over the place I can't find a trivial way of putting in an accurate test without refactoring.