Bump coverage from 4.5.3 to 4.5.4 (#3950)

Bumps [coverage](https://github.com/nedbat/coveragepy) from 4.5.3 to 4.5.4.
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](nedbat/coveragepy@coverage-4.5.3...coverage-4.5.4)

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

Author: dependabot-preview[bot]

requirements/ci-wheel.txt

@@ -5,7 +5,7 @@ async-timeout==3.0.1
 Brotli==1.0.7
 cchardet==2.1.4
 chardet==3.0.4
-coverage==4.5.3
+coverage==4.5.4
 gunicorn==19.9.0
 multidict==4.5.2
 pytest==5.0.1