Coverage seems more plausible now

.coveragerc

+[run]
+branch = True
+source = core,util,grady
+omit =
+    core/migrations/*
+    core/apps.py
+    core/admin.py
+
+[report]
+ignore_errors = False
+
+[html]
+directory = coverage_html

.gitlab-ci.yml

@@ -17,5 +17,5 @@ test:
         variables:
                 DATABASE_URL: "postgresql://postgres:postgres@postgres:5432/$POSTGRES_DB"
         script:
-                - coverage run --source="core,util" manage.py test --noinput
+                - coverage run manage.py test --noinput
                 - coverage report --skip-covered