notifier_test: fix failing tests
notifier_test: fix failing tests

Running the test suite locally yields 3 failures.

This is probably because some of the tests were catered for one machine (or CI),
so that they can pass only there. However on my computer gobrake collects
slightly different information.

Therefore, by making our expectations a bit more loose, we can make the tests
pass everywhere.

airbrake/gobrake