This pull request properly sets the events EventJoinLeave and EventTopicChange for messages from the RocketChat bridge and drops messages which are neither one of those events nor plain messages.
For an unknown reason we get duplicate messages (from the same channel)
using the realtime API when we have > 1 channel subscribed on.
Solution for now is caching the message ID in a LRU cache and ignoring
the duplicates.
This should be reviewed when we have actual editing support from the
realtime API
* Add support for editing/deleting messages
* Add support for uploading files
* Add support for avatars
* Use the Rocket.Chat.Go.SDK
* Use the rest and streaming api
