Totally remove url formatting

I think I left in the square brackets thinking it would be helpful, but it's messing up other hubot scripts:
https://www.evernote.com/shard/s27/sh/4cf39de9-2038-494a-aed7-4f15166eb5a8/9b006d210c324cf0db471fe4ccc04700

We should probably just remove it outright.