Add support for django-jinja.

[rlr]

This moves the Jinja2 helpers to templatetags/jinja_waffle_tags.py
so that the django infra always imports the file and they get loaded.
It tries using both jingo and django-jinja.

This also adds testing with Django 1.8 to the tox settings. Django 1.8
is only tested with django-jinja.

r?

[rlr]

hmm, I need to tweak travis.yml to run django 1.8... On it.

[willkg]

Nit: This uses " but should use '.

[willkg]

I think this looks ok. I had some minor nits but they're probably not that important.

The one thing I was thinking about was whether truncating waffle/helpers.py and then moving that code to waffle/templatetags/jinja_template_tags.py was a good idea or whether it'd be better to have the jingo specific code in waffle/helpers.py and not mix it with the django-jinja stuff in waffle/templatetags/jinja_template_tags.py.

Maybe that's academic, though.

@jsocol If there's anything else I can do here, let me know. I don't want to rush you, but the sooner this lands, the better. I'm totally game for trading favors (e.g. you spend some time on this and I spend some time helping you with something else) if that helps.

[willkg]

This has been around for a month and a half now. We need to move forward, so I'm going to fork django-waffle for now and we'll use my fork.

If there's anything I can do to help get this landed, let me know.

[jsocol]

I added @willkg to this repo—we talked about it offline a little while ago and I think it slipped off both our plates. I'm actively looking for more help maintaining this and a few other repos, too.

That said, the next release has got to be 0.10.2, then I'll get to #137 in 0.10.3, I guess, before wrapping up the work in 0.11.

[willkg]

I'm a huge fan of what @jsocol just did with #180. Given that solves the problems we were solving here, I'm closing this one out.