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

tests/typecheck/utils/test_decorators.yml

@@ -0,0 +1,20 @@
+-   case: method_decorator_class
+    main: |
+      from django.views.generic.base import View
+      from django.utils.decorators import method_decorator
+      from django.contrib.auth.decorators import login_required
+      @method_decorator(login_required, name='dispatch')
+      class TestView(View): ...
+      reveal_type(TestView())  # N: Revealed type is 'main.TestView'
+-   case: method_decorator_function
+    main: |
+      from django.views.generic.base import View
+      from django.utils.decorators import method_decorator
+      from django.contrib.auth.decorators import login_required
+      from django.http.response import HttpResponse
+      from django.http.request import HttpRequest
+      class TestView(View):
+          @method_decorator(login_required)
+          def dispatch(self, request: HttpRequest, *args, **kwargs) -> HttpResponse:
+              return super().dispatch(request, *args, **kwargs)
+          reveal_type(dispatch)  # N: Revealed type is 'def (self: main.TestView, request: django.http.request.HttpRequest, *args: Any, **kwargs: Any) -> django.http.response.HttpResponse'

tests/typecheck/utils/test_functional.yml

@@ -0,0 +1,18 @@
+-   case: cached_property_class_vs_instance_attributes
+    main: |
+      from django.utils.functional import cached_property
+      from typing import List
+
+      class Foo:
+          @cached_property
+          def attr(self) -> List[str]: ...
+
+          reveal_type(attr)      # N: Revealed type is 'django.utils.functional.cached_property[builtins.list*[builtins.str]]'
+          reveal_type(attr.name) # N: Revealed type is 'builtins.str'
+
+      reveal_type(Foo.attr)      # N: Revealed type is 'django.utils.functional.cached_property[builtins.list*[builtins.str]]'
+      reveal_type(Foo.attr.func) # N: Revealed type is 'def (*Any, **Any) -> builtins.list*[builtins.str]'
+
+      f = Foo()
+      reveal_type(f.attr)        # N: Revealed type is 'builtins.list*[builtins.str]'
+      f.attr.name                # E: "List[str]" has no attribute "name"