With eventlet 0.16, it becomes possible to run Oslo Messaging tests on
Python 3 with eventlet.
This change ports the zmq driver to Python 3:
* encode the topic explicitly to UTF-8
* use a list comprehension instead of map() to also get a list
on Python 3 (not a generator)
The following eventlet change is needed to run tests:
Related eventlet issue:
I will propose a different change to enable tests with eventlet enabled
when a release of eventlet including this fix will be available.