Add failling multi task test

This is creating a failing unit test to show a problem that we are facing with using neuter. Essentially your multi test functionality doesn't seem to be quite right. 

I think this may be as a result of https://github.com/trek/grunt-neuter/pull/31/files because it seems to be the opposite of https://github.com/trek/grunt-neuter/issues/30 i.e. it doesn't include any includes that were previously neutered. 

just be aware that this pull request includes https://github.com/trek/grunt-neuter/pull/49 because i needed that to get grunt default to work