Add support for redirect command

[egueli]

My Python library was failing due to unsupported command from server. Turns out it was a redirect request, that wasn't implemented yet in Python lib. Here's the implementation.

[antohaUa]

Hi Egueli!
Before all - thx a lot for investigating redirect feature and creating this pull request.

Two things that i would like to discuss with you:

1. If we have redirect message and reply status NO DATA we always should do connection redirect?
   Is it possible that redirect message will have other statuses? Should we handle them?
   You see I am not familiar enough with redirect feature - thus would like with your help to clarify library expectations and possible corner cases.
2. In your pull request pay attention that Connection is Parent class for Blynk class - so we can just within exception handling modify self.port = <new_port> self. server = that already available for us. Next connect ( that usually goes after disconnect :) should do all further staff. No need to use Connection.init()

Thx in advance for your replies

[egueli]

Hi! I'll try to answer:

1. I'm not familiar with the redirect command either, I just analyzed what kind of message and status was being sent by the server. I haven't found any documentation about the protocol, so I made an educated guess that the redirect command only happens once after the authorization is completed. It might happen that STATUS_NO_DATA is sent for other reasons. I can try making the code react specifically toMSG_REDIRECT.
2. I'll try that, thanks!