Bump hypothesis from 5.8.0 to 5.16.0 in /src/requirements (#549)

Bumps [hypothesis](https://github.com/HypothesisWorks/hypothesis) from 5.8.0 to 5.16.0.
- [Release notes](https://github.com/HypothesisWorks/hypothesis/releases)
- [Commits](https://github.com/HypothesisWorks/hypothesis/compare/hypothesis-python-5.8.0...hypothesis-python-5.16.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

src/requirements/dev.txt

@@ -7,5 +7,5 @@ codecov==2.1.4
 black==19.10b0
 pre-commit==2.4.0
 isort==4.3.21
-hypothesis==5.8.0
+hypothesis==5.16.0
 flake8==3.8.2