move to custom pytest plugin test runner, fix tests, add Any fallback to ForeignKey

mypy_django_plugin/monkeypatch/__init__.py

@@ -0,0 +1,5 @@
+from .dependencies import (load_graph_to_add_settings_file_as_a_source_seed,
+                           inject_dependencies,
+                           restore_original_load_graph,
+                           restore_original_dependencies_handling)
+from .contexts import replace_apply_function_plugin_method