Implement restart command

[agarzola]

So we don’t have to bug you with it every time the bot is wonky.

I can see this proving useful during development, then once it’s more stable ignore the command unless it comes from a small group of trusted users to avoid abuse.

[vendion]

This would actually have limited uses in development, as the source code would need compiled after changes.

[acedrew]

What would prevent us from firing a CI task off?

[vendion]

CI task?