This commit contains the first working view test
for the `request_commentaries` view.

Merge branch 'refactor-theses' of https://bitbucket.org/scipostdev/scipost_v1 into commentaries/wip-jorran

Move form validation and saving of instances
to the form class. From here you are able to instantly
save your validated form to the database. Further
reduces the size of the views.
Form may need error handling on not having
found a Contributor before saving the form instance.

You can now just call ContributorFactory() to get a freshly instantiated
Contributor to be used for testing purposes.

You can use these UserFactory to create a new user with an
associated Contributor. I could not get it to work the other way around.

Create fixtures for contributors, groups and permissions.

A blank domain throws an error in /theses/.
I've also installed factory_boy (pip install -r requirements.txt
to get it) and set up a ThesisLinkFactory and a unit tests that
tests whether ThesisLink validates for a blank domain field.

Not sure if this is exactly how you're supposed to validate
a model, but it's a start. First unit test of the project, whoohoo!

This is recommended. Also give names like
MASTER_THESIS = 'MA' to avoid magic strings and allow for easy
reference, e.g. thesis.type = ThesisLink.MASTER_THESIS. This sort
of thing helps in maintainability of the codebase, since if we want
to change the abbreviation to 'MASTER' for some reason, we have it
defined in one place, and not in 100 places in the code.

test_forms.py, test_models.py, test_views.py, as per
recommendation of the two scoops book.

Also slightly pep-improves the models and views.

Lost order argument in query for CommentarySearchForm
results in the last commit.

Reduce the amount of logic in the `commentaries` and
`browse` views methods in the `Commentaries` app. Further,
added a return method to the `CommentarySearchForm` to help thin
out code in the view.

Implemented basic modelmanager on Commentary
model. Created `vetted` and `awaiting_vetting` methods
and ipmlemented to few view methods.

Commentary model inherits from TimeStampedModel now. It
also includes migrations related to the inheritance:
 - Add added field on Commentary
 - Alter field last_activity on Commentary

Right now, this only creates a contributor based on a username.
But I hope that, in the future, we can populate an entire development
database with this command.

The core model is extended with an abstract model called
TimeStampedModel. Future and existing models should
inherit from this model to include the default timestamp fields.

- Alter field in_agreement on comment
- Alter field in_disagreement on comment
- Alter field in_notsure on comment
- Alter field is_cor on comment

I've opted for hanging indentation

foo = long_function_name(
    var_one, var_two,
    var_three, var_four)

instead of aligning with opening delimiter

foo = long_function_name(var_one, var_two,
                         var_three, var_four)

because the former makes more sense to me. See
https://www.python.org/dev/peps/pep-0008/#indentation

First pull request :-)