Merge remote-tracking branch 'mturilin/master'

* mturilin/master:
  addition admin check
  Django admin support with tests
  changed None checking
  added proper support for TypedChoiceField in Django Admin
  Add tests for creating a new admin form
Bump to 0.3.0
Ensure Django uses the label for displaying
Bump to 0.3.1
Fix 'Labels' class in Python 3.

In Python 3, the attrs dict will already be an _EnumDict, which has a
separate list of member names (in Python 2, it is still a plain dict at this
point).
Fix unit test error on Python 3
Add 'deconstruct' method for Django 1.7 migration support
Merge pull request #13 from samh/master

Fix 'Labels' class in Python 3 (fixes unit test)
Merge pull request #14 from mturilin/master

enabled support for filtering in admin for EnumIntegerField
Merge pull request #15 from samh/django17

Add 'deconstruct' method for Django 1.7 migration support
Bump version to 0.4.0
Added (failing) tests for enums with value zero
Handles zero-valued enums correctly
Merge remote-tracking branch 'stuglaser/zero_valued_enums'

* stuglaser/zero_valued_enums:
  Handles zero-valued enums correctly
  Added (failing) tests for enums with value zero
Bump to 0.4.1
fixed '__str__ returned non-string'
Bump to 0.4.2
use builtin enums available since Python 3.4
added six back as dependency for Python >=3.4
Merge branch 'use_builtin_enums'

* use_builtin_enums:
  added six back as dependency for Python >=3.4
  use builtin enums available since Python 3.4