Update codecov to 2.1.12

[pyup-bot]

This PR updates codecov from 2.1.11 to 2.1.12.

Changelog

2.1.12

Fixes
- 322 Add Cirrus CI

Dependencies and Misc
- 311 Bump coverage from 5.3 to 5.3.1
- 312 Bump coverage from 5.3.1 to 5.4
- 314 Bump coverage from 5.4 to 5.5
- 320 Upgrade to GitHub-native Dependabot

Links

• PyPI: https://pypi.org/project/codecov
• Changelog: https://pyup.io/changelogs/codecov/
• Repo: https://github.com/codecov/codecov-python

[pyup-bot]

Closing this in favor of #604