add test file for schemas

tests/app/test_schemas.py

@@ -0,0 +1,10 @@
+def test_job_schema_doesnt_return_notifications(sample_notification):
+    from app.schemas import job_schema
+
+    job = sample_notification.job
+    assert job.notifications.count() == 1
+
+    data, errors = job_schema.dump(job)
+
+    assert not errors
+    assert 'notifications' not in data