Bump coverage from 4.5.4 to 5.0.1

Bumps [coverage](https://github.com/nedbat/coveragepy) from 4.5.4 to 5.0.1.
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](nedbat/coveragepy@coverage-4.5.4...coverage-5.0.1)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

requirements-ci.txt

@@ -1,4 +1,4 @@
 pytest==5.2.4
 pytest-cov==2.8.1
-coverage==4.5.4
+coverage==5.0.1
 pycodestyle==2.5.0