Add support for ZeroMQ pub/sub for messaging #18
Description
Feature Request
As a use, I want to be able to use ZeroMQ pub/sub as a transport mechanism for compas_eve sharing the same generic API so that I can choose the best technological backend for different projects without having to re-learn or re-implement new tools.
Details
Currently, compas_eve supports in-memory and MQTT transports, but it would be desirable that more transport backends are added and can be easily swapped without having to change the client logic (beside the selection of the backend).
In this particular case, I would like to have ZeroMQ pub/sub transport available.
Describe the solution you'd like.
The ideal solution implements a new transport called ZeroMQTransport inheriting from the base Transport class, and implement equivalent logic to the one in the MqttTransport implementations (mostly base off of the paho one), so that the exact same pub/sub mechanics can be used.