Update hypothesis requirement from <4.56.2 to <4.56.4

Updates the requirements on [hypothesis](https://github.com/HypothesisWorks/hypothesis) to permit the latest version.
- [Release notes](https://github.com/HypothesisWorks/hypothesis/releases)
- [Commits](HypothesisWorks/hypothesis@hypothesis-ruby-0.0.1...hypothesis-python-4.56.3)

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

Author: dependabot-preview[bot]

test_requirements.txt

@@ -1,4 +1,4 @@
 pytest<6
-hypothesis<4.56.2
+hypothesis<4.56.4
 coverage==5.0.1
 attrs==19.3.0