The tests were failing on python 2 due to the fact that the __init__.py
wasn't written so it wasn't a valid module. With this commit we now
also fully leverage pytest functionality to handle temporary paths for
us.

Since there is no way to override SlugField and AutoSlugField in existing Oscar models, it was decided to pass `allow_unicode` parameter if this setting enable. This allows to achieve backwards compatibility with Django versions under 1.9, when this parameter was not supported yet. If parameter specified in the field expliticly - we do not override it, which allow to control slug fields individually in a normal way. For the reasons, explained above, standard SlugField was replaced with a custom one with the single slight change - control over `allow_unicode` parameter by the mentioned setting.

The tests check if the year 2010 is a valid option but since only the
last 5 years are rendered this is no longer the case. For now I've
changed the tests to check if 2014 is valid which should be the case the
next few years. A better option is to use the `freezegun` module in the
future.

In Django 1.9 the decorator from six is used so simplify the test to
just check for a __unicode__ method

Replace 'assert' with 'assert*' method.

Convert tests.unit.forms.widget_tests to use TestCase class.

Convert bankcard tests to use TestCase.

Convert tests.unit.logging_tests to use TestCase.

Currently, handle_payment_event defaults lines and line_quantities to None,
however, calling it with these defaults will result in an exception being
raised in validate_payment_event because it expects iterables.

This commit also adds tests to cover validate_payment_event.

Fixes stockrecord availability validation message in the case when stock is lower than allocation. Previously the message that appeared contained negative numbers. For example: "a maximum of -1 can be bought". Now it will display: "no stock available"

Create a factory module per app and move them under the new
oscar.test.factories module.

I broke this in 6439a95. Use pytest to paramatrize this in a proper
way

This also removes the attr() marking of tests. This can be implemented
in pytest with marking the tests with a custom marker if required.

We got support for varying the tax rate per product in #1727. This
commit does some follow-up work.

Closes #1727.

str.decode doesn't exist in Python 3 anymore, solve it using the
smart_text function from django.utils.encoding.

This fixes #1708

The offer tests contained a stray test case that I suppose was once
intended as a base class for all the other tests. But it's only used
twice, and for very little gain, so let's delete it.

Django now throws a ValueError when an unsaved instance is assigned:
https://docs.djangoproject.com/en/1.8/releases/1.8/#assigning-unsaved-objects-to-relations-raises-an-error

This commit changes the offending lines to create objects in the
database instead. But I don't understand why I don't need to make
the same changes for e.g. the country factory.

But I don't really care, as long as the tests pass. I'm guessing it has
something to do with factory-boy and the get_or_create statement.

Unfortunately, this will make our test suite slower. But to make up for
it, Django 1.8 introduces the setUpTestCase method, which we can use
once Django 1.7 is removed.

Add the tests/unit/search/__init__.py so that nose can discover the 
tests in this directory.

The changes should be obvious and non-controversial. Under Django 1.7+,
the AppConfig is used to register signal receivers instead of just
registering then when models are registered.

This removes all the bits and bobs where we referenced South, or added
some code supporting it. Documentation will be updated in a later
commit, together with other Django changes.

It's such a common error, we should try and give a friendly error
message when it occurs.

Closes #1603.

Working on sets causes a random order of returned fields while using
existing_user_fields as reported in django-oscar/django-oscar#1597.
Changed to work only on lists, which remain correct
order.

Closes #1605.
Closes #1597.

Applicator.get_basket_offers() checks for applicable basket offers using
something like if voucher.is_available_to_user(user) (see
https://github.com/django-oscar/django-oscar/blob/master/src/oscar/apps/offer/utils.py#L99).
However, the return value of is_available_to_user() is a 2-tuple, so
this will always evaluate to True.

Closes #1647

Specifying `excludes` is deprecated in Django 1.7 and not supported in
Django 1.8.

The config was picking the wrong directory so the custom test templates
were not used during tests.

Notes

- Fix missing i18n load tags
- Remove mixed tab/space indentation
- Add two settings tests

PR #1645 pointed to an issue with phone numbers. After digging into the
code for a while, I opted to redo the phone number field implementation
according to the Django documentation. It always takes me a bit of time
to grok descriptors; the new implementation avoids them.

Note that this does not fix any issue; it's just a simplication done
while searching for the bug.

This gets quite fiddly since dashboard apps aren't identified by a
single app label. We need to special-case them in a few places.

Issue #1503 was rather embarrassing and highlighted it's about time we
have tests for the form. This vets the logic in the PhoneNumberMixin as
well.