Matterbot
Matterbot is a super-simple bot-client for Mattermost.
Why not Hubot?
Hubot is probably awesome if you need a full-time mega-bot army. If you just need a tiny little bot to test an idea, or to prank your friends, you could use Matterbot. It's just a library, and you can be up and running in just a few lines of code.
How do I use it?
Better docs are coming soon. For now, you'll have to clone the repo, and check out the examples folder for some basic ideas.