Update pytest-runner to 4.4

[pyup-bot]

This PR updates pytest-runner from 4.2 to 4.4.

Changelog

4.4

===

* 43: Detect condition where declarative config will cause
errors and emit a UserWarning with guidance on necessary
actions.

4.3.1

=====

* 43: Re-release of 4.2 to supersede the 4.3 release which
proved to be backward-incompatible in that it requires
setuptools 30.4 or possibly later (to install). In the future, a
backward-incompatible release will re-release these changes.
For projects including pytest-runner, particularly as
``setup_requires``, if support for older setuptools is required,
please pin to ``pytest-runner < 5``.

4.3

===

(Pulled from PyPI due to 43)

* 42: Update project metadata, including pyproject.toml declaration.

Links

• PyPI: https://pypi.org/project/pytest-runner
• Changelog: https://pyup.io/changelogs/pytest-runner/
• Repo: https://github.com/pytest-dev/pytest-runner