Use setUpTestData() to speed up tests

Pylint's `bad-classmethod-argument` is disabled for each definition
to avoid rewriting the method bodies just to rename `self` → `cls`.
This can be done gradually, as the setUpTestData methods are modified
along the way.

bookwyrm/tests/test_context_processors.py

@@ -11,9 +11,9 @@ from bookwyrm.context_processors import site_settings
 class ContextProcessor(TestCase):
     """pages you land on without really trying"""
 
-    def setUp(self):
+    @classmethod
+    def setUpTestData(self):  # pylint: disable=bad-classmethod-argument
         """we need basic test data and mocks"""
-        self.factory = RequestFactory()
         with patch("bookwyrm.suggested_users.rerank_suggestions_task.delay"), patch(
             "bookwyrm.activitystreams.populate_stream_task.delay"
         ), patch("bookwyrm.lists_stream.populate_lists_task.delay"):
@@ -28,6 +28,10 @@ class ContextProcessor(TestCase):
         self.anonymous_user.is_authenticated = False
         self.site = models.SiteSettings.objects.create()
 
+    def setUp(self):
+        """other test data"""
+        self.factory = RequestFactory()
+
     def test_theme_unset(self):
         """logged in user, no selected theme"""
         request = self.factory.get("")