Missing pyzmq dependency causes import errors

[avinxshKD]

After cloning the repo and ran into this:

$ pip install -r requirements.txt
$ python -c "import concore"
ModuleNotFoundError: No module named 'zmq'

Looks like pyzmq isn't in requirements.txt or setup.py, but concore.py imports it on line 7 and uses it for the ZeroMQPort stuff. Had to manually install it to get things running.

Should probably add pyzmq>=25.0.0 to both files so fresh installs actually work.

[avinxshKD]

What do you think @pradeeban? worked upon the fix, ready to raise a pr

[pradeeban]

@avinxshKD sure, go ahead.