More and better test failure messages

lostplaces/lostplaces_app/tests/models/test_abstract_models.py

@@ -72,9 +72,21 @@ class SubmittableTestCase(ModelTestCase):
         )
         self.assertTrue(
             submitted_by.null,
-            msg='Expecting the sub'
+            msg='Expecting %s to has null=True' % (
+                str(submitted_by)
             )
-        self.assertTrue(submitted_by.blank)
+        )
+        self.assertTrue(
+            submitted_by.blank,
+            msg='Expecting %s to has blank=True' % (
+                str(submitted_by)
+            )    
+        )
         self.assertEqual(
-            submitted_by.remote_field.on_delete, models.SET_NULL)
+            submitted_by.remote_field.on_delete,
+            models.SET_NULL
+            msg='Expecting %s to be null when reference is delete (models.SET_NULL)' % (
+                str(submitted_by)
+            )
+        )