[arch-devops] Archweb upgrade to django to 1.11

[Jelle van der Waa]

I've made a PR to update archweb to 1.11 the latest LTS version of
django. [1]
It's running on the staging env currently and no particular bugs have
been found yet. Note that the staging env does not sync new packages,
which I would love add soon (tm). [2]

When this is merged, I'd like to deploy it as soon as possible on our
production env. After this merge I want to focus on Python 3 / Django
2.0 although this is not a LTS release. (Python 3 alone should be enough
work tbh).

When would be a good time for an upgrade? Angvp / grazzolini please
review the PR so it can be merged.

[1] https://github.com/archlinux/archweb/pull/88
[2] https://archweb-dev.archlinux.org/

-- 
Jelle van der Waa