Add support to cryptography 37.0.0 and above

[kairoaraujo]

The current OwnCA supports version cryptography 3.4.8. There are changes in 35.0.0 and higher version that requires some changes on the OwnCA

[lawndoc]

I can help work on this. Should we create a feature branch first or just fork from master?

[kairoaraujo]

Just fork from the master