• Cleanup cluster state information on a node which is being gracefully removed
  from the cluster so if it is restarted it comes back up as a stand-alone node
  and won't try to reconnect to the remaining nodes.
• Upgraded dependency swc. Improves memory and cpu usage by fixing node clock
  update bug.
• Set queue expiration (persistent_client_expiration) timer on queues after a
  broker restart (#1071).
• Fix status page to show all cluster nodes (#1066).
• Fix Lua json.decode() when decoding empty Json objects (#1080).
• Fix vmq_diversity cache invalidation timing issue when a client reconnects
  right after a disconnect (#996).
• Fix retry of MQTT publish frame in vmq_bridge (#1084).
• Fix outgoing qos2 message id bug (#1045).