Add organisations model and create dao

tests/app/dao/test_organisations_dao.py

@@ -0,0 +1,14 @@
+import pytest
+
+from app.dao.organisations_dao import dao_create_organisation
+from app.models import Organisation
+
+from tests.app.db import create_organisation
+
+
+def test_create_organisation(notify_db, notify_db_session):
+    organisation = create_organisation()
+
+    assert Organisation.query.count() == 1
+    organisation_from_db = Organisation.query.first()
+    assert organisation == organisation_from_db