Support Python 3

[jonnor]

gevent 1.1alpha2 apparently supports it. Might need work in Haigha though

Tests must run both Py 2 and Py 3

[jonnor]

gevent 1.2 has support, howeber Haigha seems currently broken on Py3 agoragames/haigha#94

[peterclemenko]

If I may make a suggestion, haigha seems to be unmaintained. Maybe porting to pika https://pika.readthedocs.io/en/0.10.0/ would be a good idea to support python 3.

[jonnor]

Now support MQTT on Python 3. #31

Porting to Pika would be the way to go for AMQP

[bergie]

Would be great to switch from gevent to asyncio https://docs.python.org/3/library/asyncio.html

Reasons:

• Part of standard library
• gevent takes a long time to install
• gevent 1.3> has trouble with Docker builds

[jonnor]

@bergie what is the problem with gevent in Docker?

Unlikely to rewrite this library to asyncio. Python 3 is supported with MQTT and in production for a year now.