Update to 2.0.13

• Add LICENSE_FILE
• Update RUN_DEPENDS: use newer django
• Relax USES=python
• Use USE_PYTHON=autoplist instead of PLIST
• Allow concurrent installation (USE_PYTHON=concurrent)
• Add NO_ARCH
• Add DOCS option
• Remove pkg-message

Changes: https://github.com/etianen/django-reversion/blob/master/CHANGELOG.rst
PR: 228128
Submitted by: Kai <freebsd_ports@k-worx.org>
Approved by: Matthew X. Economou <xenophon+fbsdports@irtnog.org> (maintainer)