Update coverage to 5.0.4

[pyup-bot]

This PR updates coverage from 5.0.3 to 5.0.4.

Changelog

5.0.4

----------------------------

- If using the ``[run] relative_files`` setting, the XML report will use
relative files in the ``<source>`` elements indicating the location of source
code.  Closes `issue 948`_.

- The textual summary report could report missing lines with negative line
numbers on PyPy3 7.1 (`issue 943`_).  This is now fixed.

- Windows wheels for Python 3.8 were incorrectly built, but are now fixed.
(`issue 949`_)

- Updated Python 3.9 support to 3.9a4.

- HTML reports couldn't be sorted if localStorage wasn't available. This is now
fixed: sorting works even though the sorting setting isn't retained. (`issue
944`_ and `pull request 945`_). Thanks, Abdeali Kothari.

.. _issue 943: https://github.com/nedbat/coveragepy/issues/943
.. _issue 944: https://github.com/nedbat/coveragepy/issues/944
.. _pull request 945: https://github.com/nedbat/coveragepy/pull/945
.. _issue 948: https://github.com/nedbat/coveragepy/issues/948
.. _issue 949: https://github.com/nedbat/coveragepy/issues/949


.. _changes_503:

Links

• PyPI: https://pypi.org/project/coverage
• Changelog: https://pyup.io/changelogs/coverage/
• Repo: https://github.com/nedbat/coveragepy

[coveralls]

Coverage remained the same at 42.065% when pulling 2620796 on pyup-update-coverage-5.0.3-to-5.0.4 into 10a4d82 on master.

[pyup-bot]

Closing this in favor of #401