To run the test suite, first, create and activate a virtual environment. Then
install some requirements and run the tests::

    $ cd tests
    $ pip install -e ..
    $ pip install -r requirements/py3.txt  # or py2.txt
    $ ./runtests.py

For more information about the test suite, see
https://docs.djangoproject.com/en/dev/internals/contributing/writing-code/unit-tests/.
