Update pytest-mock to 1.4.0

[pyup-bot]

There's a new version of pytest-mock available.
You are currently using 1.3.0. I have updated it to 1.4.0

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

Changelog

1.4.0

---

• New configuration variable, mock_use_standalone_module (defaults to False). This forces
  the plugin to import mock instead of unittest.mock on Python 3. This is useful to import
  and use a newer version than the one available in the Python distribution.

• Previously the plugin would first try to import mock and fallback to unittest.mock
  in case of an ImportError, but this behavior has been removed because it could hide
  hard to debug import errors (68_).

• Now mock (Python 2) and unittest.mock (Python 3) are lazy-loaded to make it possible to
  implement the new mock_use_standlone_module configuration option. As a consequence of this
  the undocumented pytest_mock.mock_module variable, which pointed to the actual mock module
  being used by the plugin, has been removed.

• DEFAULT <https://docs.python.org/3/library/unittest.mock.htmldefault>_ is now available from
  the mocker fixture.

.. _68: pytest-dev/pytest-mock#68

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

Happy merging! 🤖

[coveralls]

Coverage remained the same at 85.714% when pulling 858dece on pyup-update-pytest-mock-1.3.0-to-1.4.0 into fc3fe36 on develop.