grunt v 0.4 task registration as an array

Thanks so much for a great project. Exactly what I was looking for--a lightweight reloader to tie into my grunt task based workflow.

I had an issue getting the tiny-lr tasks to run with Grunt v.04, and found the task registration wasn't being passed as an array, but as the v0.3 style of space separated tasks.

I couldn't quite grok your testing scenario for the grunt example, but here's a PR anyhow.