Fixes bug introduced in https://github.com/frankwallis/gulp-hub/pull/10: Changes generated subtask function signature to only include callback parameter if actual subtask has one either.
Orchestrator checks task function signature, and if callback parameter is present but never called, that task will never finish. This could be seen in the examples. Sorry about that! :-(
Merge pull request #11 from simonihmig/master

Fix for wrong subtask function signature