Update check-manifest to 0.38

[pyup-bot]

This PR updates check-manifest from 0.37 to 0.38.

Changelog

0.38

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

- Add Python 3.7 support.

- Drop Python 3.4 support.

- Added GitHub templates to default ignore patterns.

- Added reading check-manifest config out of ``tox.ini`` or ``pyproject.toml``.

Links

• PyPI: https://pypi.org/project/check-manifest
• Changelog: https://pyup.io/changelogs/check-manifest/
• Repo: https://github.com/mgedmin/check-manifest

[coveralls]

Coverage increased (+0.06%) to 30.441% when pulling bbc48e3 on pyup-update-check-manifest-0.37-to-0.38 into 8613d9d on master.

[pyup-bot]

Closing this in favor of #298