Bump flake8-bugbear from 20.1.4 to 20.11.1 (#645)

Author: dependabot[bot]

requirements/requirements_dev.txt

@@ -5,7 +5,7 @@ black==20.8b1
 dlint==0.11.0
 flake8==3.8.4
 flake8-bandit==2.1.2
-flake8-bugbear==20.1.4
+flake8-bugbear==20.11.1
 hypothesis==5.41.3
 placebo==0.9.0
 pre-commit==2.8.2