fix($mochaTestFramework): Fix testFramework addTest hook

[jeznag]

It was breaking for BDD tests

issue #7

[simondel]

Thanks for taking the time to make changes to the code! Could you add some tests so we know the bug won't come up again? Feel free to add actual test/source files to the test resources folder.

[nicojs]

@jeznag wow you found my dirty hack :)

I understand that the code doesn't break anymore, but will the filtering work for BDD tests? I've got the feeling that tests aren't filtered and thus: every test runs for every mutant. In that case we should just remove this feature all together and throw an error instead.

Also see my update on stryker-mutator/stryker-mutator.github.io#29 for more info about the history of this issue.