Update coverage to 4.5.4

[pyup-bot]

This PR updates coverage from 4.5.2 to 4.5.4.

Changelog

4.5.4

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

- Multiprocessing support in Python 3.8 was broken, but is now fixed.  Closes
`issue 828`_.

.. _issue 828: https://github.com/nedbat/coveragepy/issues/828


.. _changes_453:

4.5.3

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

- Only packaging metadata changes.


.. _changes_452:

Links

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

[codecov]

Codecov Report

Merging #178 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #178   +/-   ##
=======================================
  Coverage   76.08%   76.08%           
=======================================
  Files           9        9           
  Lines         322      322           
  Branches       37       37           
=======================================
  Hits          245      245           
  Misses         68       68           
  Partials        9        9

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