This is a minor release that adds support for websocket proxies, resolves a potential panic, and sets the DUP flag when resenting PUBLISH packets.

#431 Add Proxy to WebsocketOptions (also logs status if connection fails) - @fulder
#489 If options.AutoReconnect is true calling Disconnect may trigger panic - @MattBrittan
#490 When resending QOS 1+ PUBLISH packets the DUP flag should be set - @MattBrittan