[NEW] security/py-pymacaroons-pynacl: Macaroon library for Python

Macaroons, like cookies, are a form of bearer credential. Unlike opaque tokens,
macaroons embed caveats that define specific authorization requirements for the
target service, the service that issued the root macaroon and which is capable
of verifying the integrity of macaroons it receives.

WWW: https://github.com/matrix-org/pymacaroons

PR: 205914
Submitted by: Brendan Molloy <brendan+freebsd@bbqsrc.net>