Add special mypy config for Python 3.6

Author: kesmit13

.pre-commit-config-py36.yaml

@@ -39,7 +39,7 @@ repos:
     hooks:
     -   id: setup-cfg-fmt
 -   repo: https://github.com/pre-commit/mirrors-mypy
-    rev: v0.971
+    rev: v0.931
     hooks:
     -   id: mypy
         additional_dependencies: [types-all]