Building the methods around async stats work

tests/app/dao/test_statistics_dao.py

@@ -0,0 +1,19 @@
+from app.dao.statistics_dao import persist_initial_job_statistics
+from app.models import JobStatistics
+from tests.app.conftest import sample_notification
+
+
+def test_should_create_a_stats_entry_for_a_job(
+        notify_db, notify_db_session, sample_service, sample_template, sample_job
+):
+    assert not len(JobStatistics.query.all())
+
+    notification = sample_notification(
+        notify_db, notify_db_session, service=sample_service, template=sample_template, job=sample_job
+    )
+
+    persist_initial_job_statistics(notification)
+
+    stats = JobStatistics.query.all()
+
+    assert len(stats) == 1