Update coverage requirement from <6.4,>=5.1 to >=5.1,<6.5

Updates the requirements on [coverage](https://github.com/nedbat/coveragepy) to permit the latest version.
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](nedbat/coveragepy@coverage-5.1...6.4)

---
updated-dependencies:
- dependency-name: coverage
  dependency-type: direct:production
...

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

requirements.txt

@@ -5,7 +5,7 @@ flake8>=3.9,<4.1
 isort>=5.9,<5.11
 
 # Testing
-coverage>=5.1,<6.4
+coverage>=5.1,<6.5
 django-webtest>=1.9,<1.10
 factory-boy>=3.2,<3.3
 pinocchio==0.4.3