Bump coveralls from 2.2.0 to 3.0.0

Bumps [coveralls](https://github.com/coveralls-clients/coveralls-python) from 2.2.0 to 3.0.0.
- [Release notes](https://github.com/coveralls-clients/coveralls-python/releases)
- [Changelog](https://github.com/coveralls-clients/coveralls-python/blob/master/CHANGELOG.md)
- [Commits](TheKevJames/coveralls-python@2.2.0...3.0.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

requirements/testing.txt

@@ -1,7 +1,7 @@
 -r production.txt
 pre-commit==2.9.3
 isort==5.7.0
-coveralls==2.2.0
+coveralls==3.0.0
 flake8==3.8.4
 flake8-isort==4.0.0
 pydocstyle==5.1.1