Bump flake8 from 3.7.9 to 3.8.4 (#737)

dependabot-preview[bot] · web-flow · commit 3aa486e4e167 · 2020-12-04T21:40:03.000Z
diff --git a/requirements.txt b/requirements.txt
@@ -1,6 +1,6 @@
 coverage==5.3
 docker==4.4.0
-flake8==3.7.9
+flake8==3.8.4
 isort==4.3.4
 -e .[sa]
 sphinx==3.3.1
