Update flake8 requirement from ==3.8.* to ==3.9.* (#134)

dependabot[bot] · web-flow · commit cabf724a48ca · 2021-03-17T08:48:45.000-06:00
diff --git a/requirements-test.txt b/requirements-test.txt
@@ -3,6 +3,6 @@ pytest-cov==2.11.*
 pytest-vcr==1.0.*
 black==20.8b1
 isort==5.7.*
-flake8==3.8.*
+flake8==3.9.*
 mypy==0.812
 freezegun==1.1.*
