Update flake8 from 3.9.2 to 4.0.1 (#627)

pyup-bot · abhinavsingh · web-flow · commit daa30d452ddf · 2021-10-29T16:58:39.000Z
Co-authored-by: Abhinav Singh &lt;mailsforabhinav@gmail.com&gt;
diff --git a/requirements-testing.txt b/requirements-testing.txt
@@ -1,7 +1,7 @@
 wheel==0.37.0
 python-coveralls==2.9.3
 coverage==6.0.2
-flake8==3.9.2
+flake8==4.0.1
 pytest==6.2.5
 pytest-cov==3.0.0
 autopep8==1.5.7
