* Add Django 1.8 to test environments in tox.ini
* Update python versions supported by Django master in tox.ini
* Don't load 'url' from template library 'future' - it is no longer
available in Django master, and is not needed in Django 1.4 and later,
which is as far back as django-constance tests
* get_cache dropped from Django master
* post_syncdb signal dropped
* django.utils.importlib dropped
There are still errors on some environments that I didn't try to
address:
* coverage seems broken on py32
* django-master seems currently broken on py27 (non-ASCII character
somewhere,
I expect django-master will be fixed soon since they still claim py27
support)
* django14 seems broken: "NoReverseMatch: u"'admin" is not a registered
namespace"
