Squash DRF deprecation warnings

[jmbowman]

The test suite had been reporting 3 deprecation warnings (which were preventing a Django REST Framework upgrade) and a ResourceWarning:

user_tasks/views.py:57
  /home/travis/build/edx/django-user-tasks/user_tasks/views.py:57: RemovedInDRF310Warning: `detail_route` is deprecated and will be removed in 3.10 in favor of `action`, which accepts a `detail` bool. Use `@action(detail=True)` instead.
    @detail_route(methods=['post'])

user_tasks/urls.py:10
  /home/travis/build/edx/django-user-tasks/user_tasks/urls.py:10: RemovedInDRF311Warning: The `base_name` argument is pending deprecation in favor of `basename`.
    ROUTER.register(r'artifacts', ArtifactViewSet, base_name='usertaskartifact')

user_tasks/urls.py:11
  /home/travis/build/edx/django-user-tasks/user_tasks/urls.py:11: RemovedInDRF311Warning: The `base_name` argument is pending deprecation in favor of `basename`.
    ROUTER.register(r'tasks', StatusViewSet, base_name='usertaskstatus')

/opt/python/3.8.0/lib/python3.8/tempfile.py:816: ResourceWarning: Implicitly cleaning up <TemporaryDirectory '/tmp/tmpxp8ex7s_'>
  _warnings.warn(warn_message, ResourceWarning)

The DRF deprecation warnings were also appearing in the edx-platform test suite, since it uses this package. This should pave the way to upgrading DRF in edx-platform to at least 3.11, since these were the last deprecation warnings reporting breakage that would occur with that version.

21:39:22  ../../edx-venv-3.8/edx-venv/lib/python3.8/site-packages/user_tasks/views.py:57
21:39:22  ../../edx-venv-3.8/edx-venv/lib/python3.8/site-packages/user_tasks/views.py:57
21:39:22  ../../edx-venv-3.8/edx-venv/lib/python3.8/site-packages/user_tasks/views.py:57
21:39:22    /home/jenkins/edx-venv-3.8/edx-venv/lib/python3.8/site-packages/user_tasks/views.py:57: RemovedInDRF310Warning: `detail_route` is deprecated and will be removed in 3.10 in favor of `action`, which accepts a `detail` bool. Use `@action(detail=True)` instead.
21:39:22      @detail_route(methods=['post'])
21:39:22  
21:39:22  ../../edx-venv-3.8/edx-venv/lib/python3.8/site-packages/user_tasks/urls.py:10
21:39:22  ../../edx-venv-3.8/edx-venv/lib/python3.8/site-packages/user_tasks/urls.py:10
21:39:22  ../../edx-venv-3.8/edx-venv/lib/python3.8/site-packages/user_tasks/urls.py:10
21:39:22    /home/jenkins/edx-venv-3.8/edx-venv/lib/python3.8/site-packages/user_tasks/urls.py:10: RemovedInDRF311Warning: The `base_name` argument is pending deprecation in favor of `basename`.
21:39:22      ROUTER.register(r'artifacts', ArtifactViewSet, base_name='usertaskartifact')
21:39:22  
21:39:22  ../../edx-venv-3.8/edx-venv/lib/python3.8/site-packages/user_tasks/urls.py:11
21:39:22  ../../edx-venv-3.8/edx-venv/lib/python3.8/site-packages/user_tasks/urls.py:11
21:39:22  ../../edx-venv-3.8/edx-venv/lib/python3.8/site-packages/user_tasks/urls.py:11
21:39:22    /home/jenkins/edx-venv-3.8/edx-venv/lib/python3.8/site-packages/user_tasks/urls.py:11: RemovedInDRF311Warning: The `base_name` argument is pending deprecation in favor of `basename`.
21:39:22      ROUTER.register(r'tasks', StatusViewSet, base_name='usertaskstatus')

Implementation notes:

• The changes to DRF usage are exact equivalents to the previous code, behavior shouldn't change.
• Added testing with each major DRF version from 3.9.x (used in edx-platform) to the latest 3.12.x
• Using a pytest session fixture to clean up the temporary directories when the test session ends. I had to upper case the variable names for them to be importable via from django.conf import settings, since test_settings.py itself isn't in an importable location.

[codecov]

Codecov Report

Merging #97 (4f426b0) into master (4e0046e) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##            master       #97   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            8         8           
  Lines          359       359           
  Branches        47        47           
=========================================
  Hits           359       359           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 4e0046e...4f426b0. Read the comment docs.