Django 1.8+ compatibility

[maryokhin]

As per the deprecation note.

[jschneier]

Thanks for this it looks great! My only concern is whether the super calls with no arguments will work on Python2.

[maryokhin]

Yes, it should work because StorageMixin is a new style class + the build would have failed otherwise.
http://stackoverflow.com/questions/54867/what-is-the-difference-between-old-style-and-new-style-classes-in-python

[mbarrien]

Wrong, argumentless super() was introduced in Python 3, and never back ported. From a Python 2.7 REPL session:

>>> class Foo(object):
...     def func(self):
...         print "Foo"
...
>>> class Bar(Foo):
...     def func(self):
...         super().func()
...
>>> Bar().func()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 3, in func
TypeError: super() takes at least 1 argument (0 given)
>>>

See first entry under Builtins at https://docs.python.org/3.0/whatsnew/3.0.html (the note about PEP 3135).

[maryokhin]

Ok, true. I don't use Python 2, didn't expect it to still be such a mess. I'll fix it.