Fix tests with Core 4.0.0.dev2

aleksis/apps/chronos/migrations/0015_drop_site.py

@@ -56,13 +56,11 @@ class Migration(migrations.Migration):
             "extralesson",
             "holiday",
             "lesson",
-            "lessonevent",
             "lessonperiod",
             "lessonsubstitution",
             "subject",
             "supervision",
             "supervisionarea",
-            "supervisionevent",
             "supervisionsubstitution",
             "timeperiod",
             "validityrange"