Implement message sending and broadcasting

[bishopBethel]

Handle message:send events: persist message to PostgreSQL, broadcast message:new to the bounty room, and trigger push notification for offline recipients.

[hinzwilliam52-ship-it]

I've got a surgical fix for this. Just running some quick local tests and will post the PR soon.

[hinzwilliam52-ship-it]

I have opened a Pull Request with the fix here: #132

Thanks!

[zhaog100]

/attempt

[zhaog100]

/attempt