Bump coverage from 5.4 to 5.5

Bumps [coverage](https://github.com/nedbat/coveragepy) from 5.4 to 5.5.
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](coveragepy/coveragepy@coverage-5.4...coverage-5.5)

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

Author: dependabot-preview[bot]

test-requirements.txt

@@ -25,7 +25,7 @@ cffi==1.14.5
     # via cryptography
 click==7.1.2
     # via black
-coverage==5.4
+coverage==5.5
     # via pytest-cov
 cryptography==3.4.6
     # via