chore: bump coveralls from 2.1.1 to 2.1.2

Bumps [coveralls](https://github.com/coveralls-clients/coveralls-python) from 2.1.1 to 2.1.2.
- [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@2.1.1...2.1.2)

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

requirements/dev.txt

@@ -2,7 +2,7 @@
 -r test.txt
 black
 coverage==5.1
-coveralls==2.1.1
+coveralls==2.1.2
 pylint
 py-githooks
 rope