MAINT: Bump hypothesis from 6.14.0 to 6.28.1

Bumps [hypothesis](https://github.com/HypothesisWorks/hypothesis) from 6.14.0 to 6.28.1.
- [Release notes](https://github.com/HypothesisWorks/hypothesis/releases)
- [Commits](HypothesisWorks/hypothesis@hypothesis-python-6.14.0...hypothesis-python-6.28.1)

---
updated-dependencies:
- dependency-name: hypothesis
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

test_requirements.txt

@@ -1,7 +1,7 @@
 cython==0.29.23
 wheel<0.36.3
 setuptools<49.2.0
-hypothesis==6.14.0
+hypothesis==6.28.1
 pytest==6.2.4
 pytz==2021.1
 pytest-cov==2.12.1