updated package setup (#485)

* updated package setup

* updated to use python 3.9

* fixed test runner

* fixed typecheck tests

* fixed discrepencies

* added override to runner

* updated travis

* updated pre-commit hooks

* updated dep

setup.cfg

@@ -1,19 +1,11 @@
-[isort]
-skip =
-  django-sources
-  django-stubs
-  test-data
-include_trailing_comma = true
-multi_line_output = 5
-wrap_length = 120
-known_first_party = mypy_django_plugin
-
 [flake8]
-exclude =
-  django-sources
-  django-stubs
-  test-data
+exclude = .*/
+select = F401, Y
 max_line_length = 120
+per-file-ignores =
+    *__init__.pyi: F401
+    base_user.pyi: Y003
+    models.pyi: Y003
 
 [metadata]
 license_file = LICENSE.txt