* Switch the port to Django 2.2 (current LTS release) as well because
Django 1.11 is End-of-Life since April. Do the same for www/py-drf-yasg.
* Repo-copy www/py-djangorestframework to www/py-djangorestframework311
which will be used as a transitional package by www/seahub until it gets
support for Django 2.2+ in the next weeks/months.
* Drop the Python 2.7 support of the remaining consumers to avoid breakage
of "bulk -a".
* Mark both repo-copied ports www/py-dj22-{djangorestframework,drf-yasg} as
deprecated because they're obsolete now.
PR: 245309
Reviewed by: sunpoet (earlier revision), ultima
Differential Revision: https://reviews.freebsd.org/D24850
ea1b10f966