Log Message:
py-zmq: updated to 18.1.0

18.1.0
- Compatibility with Python 3.8 release candidate by regenerating Cython courses \ 
with Cython 0.29.13
- bump bundled libzmq to 4.3.2
- handle cancelled futures in asyncio
- make :meth:`zmq.Context.instance` fork-safe
- fix errors in :meth:`zmq.Context.destroy` when opening and closing many sockets