Support pyopenssl 21

[traylenator]

With the new 8 release the optional requirement on pyopenssl is

PyOpenSSL = {version = "^20.0.1", optional = true}

that resolves to <21 so the new version 22

https://pypi.org/project/pyOpenSSL/

is not supported ?

Can the requirement be relaxed?

[traylenator]

https://www.pyopenssl.org/en/stable/changelog.html
changelog looks okay at least.

[jasonrbriggs]

Note: Have removed PyOpenSSL altogether and moved to the latest cryptography module version (37.0.1). See version 8.0.1: https://pypi.org/project/stomp.py/8.0.1/