Update coverage to 5.1

[pyup-bot]

This PR updates coverage from 5.0.4 to 5.1.

Changelog

5.1

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

- The JSON report now includes counts of covered and missing branches. Thanks,
Salvatore Zagaria.

- On Python 3.8, try-finally-return reported wrong branch coverage with
decorated async functions (`issue 946`_).  This is now fixed. Thanks, Kjell
Braden.

- The :meth:`~coverage.Coverage.get_option` and
:meth:`~coverage.Coverage.set_option` methods can now manipulate the
``[paths]`` configuration setting.  Thanks to Bernát Gábor for the fix for
`issue 967`_.

.. _issue 946: https://github.com/nedbat/coveragepy/issues/946
.. _issue 967: https://github.com/nedbat/coveragepy/issues/967


.. _changes_504:

Links

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