Update pytest-mock to 1.6.0

[pyup-bot]

There's a new version of pytest-mock available.
You are currently using 1.5.0. I have updated it to 1.6.0

These links might come in handy: PyPI | Changelog | Repo

Changelog

1.6.0

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• The original assertions raised by the various Mock.assert_* methods
  now appear in the failure message, in addition to the message obtained from
  pytest introspection.
  Thanks quodlibetor_ for the initial patch (79_).

.. _quodlibetor: https://github.com/quodlibetor

.. _79: pytest-dev/pytest-mock#79

Got merge conflicts? Close this PR and delete the branch. I'll create a new PR for you.

Happy merging! 🤖

[codecov-io]

Codecov Report

Merging #356 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #356   +/-   ##
=======================================
  Coverage   82.66%   82.66%           
=======================================
  Files          50       50           
  Lines        1690     1690           
  Branches      161      161           
=======================================
  Hits         1397     1397           
  Misses        267      267           
  Partials       26       26

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