Installation of cryptography fails for Azure dependencies on windows

[jeppe742]

From version 3.3 cryptography switched from compiled wheels for each python version, to using the ABI3 format.
This, however, requires a very recent version of pip to work.
pip==20.0 seemed to do the trick for me

Otherwise, pip will fail to find a compiled wheel and try to compile it from source. This requires you to have OpenSSL installed

[jeppe742]

see pyca/cryptography#5669