Fix flake8-docstrings D401

* The first line should be in imperative mood.
Use tuple for __all__ in __init__.py

* Avoid possibility that __all__ can be mutated confusing
  flake8-docstrings
Fix flake8-docstrings D400

* The first line should end with a full stop.
Fix flake8-docstrings D102 and D103

* Omit docstrings for setUp methods in TestCases
* D102: Public method docstring missing.
* D102: Public function docstring missing.
Tweak test docstring to refer to url, not slug
Add flake8-docstrings to test_requirements.txt

Disable flake8 warnings for D100, D203 and D204
* D100: Module docstring missing.
* D203: 1 blank line required before class docstring.
* D204: 1 blank line required after class docstring.
Split long oneline docstring into multiple lines

* D200: One-line docstrings should fit on one line with quotes.
Fix flake8-docstrings D101

* Omit docstrings for test classes.
* D101: Public class docstring missing.
Merge branch 'master' into flake8-docstring
Fix flake8-docstrings D400 and D401
Move flake8-docstrings into docstring_requirements

* Allow use of flake8-docstrings locally without causing travis build
  failures.
Add missing docstrings for the cms app
Merge branch 'master' into flake8-docstring

Conflicts:
	conman/redirects/tests/factories.py
Move flake8-docstrings back into test_requirements

* Explicitly remove flake8-docstrings from travis builds
Simplify repetitive docstring
Merge pull request #31 from Ian-Foote/flake8-docstring

Fix flake8-docstring warnings