Zmq-windows version too old

[kumori123]

I want to use zmq-windows for compiling with ocaml 4.14.0, but I found that the only version of zmq-windows only supported ocaml < 4.05。Is that any way that I can update the version of zmq-windows? In my occasion I cannot downgrade ocaml.
Thank you!

[toots]

Sure. Feel free to submit a pull request, I'd be happy to review and merge it.