Catch Sentry errors

[mrunkel]

Hey, I would love to see herd be able to catch exceptions thrown by sentry. We use sentry.io in our production sites, but it's not great to have all your typos sent to the cloud and shared with all your teammates. :)

We used to use buggreator, but now that we've moved away from docker, it doesn't make a lot of sense.

If you need help implementing, I would love to give it a shot. (if you allow outside collaboration).