We need to explicitely specify the location where pytest looks for tests
to prevent the kind of nasty error described here:

  https://tox.readthedocs.io/en/latest/example/pytest.html#known-issues-and-limitations

Also note that migrations scripts are excluded from flake8 in the tox file.

related to T1247.

We do use the pytest-django plugin to manage the django db setup magic,
so with this change, we can run tests without an existing db, or starting
a postgres db dedicated to the tests using pifpaf.

related to T1261

tests_require != test_requires

Summary: Part of T1261

Test Plan: Still running 104 tests after the change

Reviewers: ardumont

Differential Revision: https://forge.softwareheritage.org/D525

related to T1242

Django 2.0 removed `django.core.urlresolvers` (which was
replaced/deprecated in favor of `django.urls` in 1.10).
Django_nose is also needed to run tests.

typo

autodoc tries to import discovered modules independently from their
runtime use.

As swh/deposit/settings holds multiple runtime settings (including
production), this wrongly tries to load the production one.

This fixes all html documentation generation.

Close T1182
Close D447

autodoc tries to import discovered modules independently from their
runtime use.

As swh/deposit/settings holds multiple runtime settings (including
production), this wrongly tries to load the production one.

This only fixes the local html documentation generation.  This does
not fix the global html documentation generation though.

Related T1182

Related T1169

Related T1169

Ids can be other types than string, join will not work on those.
This commit fixes it.

This does the dependencies declaration the same way the
python3-swh.lister package does it.

Close T1154

Related T1154

Related T1152