Merge pull request #618 from pre-commit/all-repos_autofix_mypy-settings

stricter mypy settings

Author: asottile

setup.cfg

@@ -80,6 +80,8 @@ disallow_any_generics = true
 disallow_incomplete_defs = true
 disallow_untyped_defs = true
 no_implicit_optional = true
+warn_redundant_casts = true
+warn_unused_ignores = true
 
 [mypy-testing.*]
 disallow_untyped_defs = false