net-mgmt/py-pysnmpcrypto: New port pysnmpcrypto

[agh_riseup.net]

Summary

The pysnmpcrypto library is an optional extension to py-pysnmp-lextudio,
to facilitate migration to updated cryptographic libraries, such as
py-cryptography.

The pysnmpcrypto library provides stronger authentication and encryption
features to the SNMP library by way of invoking stronger crypto
algorithms.

https://github.com/pysnmp/pysnmpcrypto