Feat: add orm for Tribes

tests/integration/test_orm.py

@@ -0,0 +1,15 @@
+from backend.adapters.orm import metadata, start_mappers
+from backend.model.tribe import Tribe
+
+
+def test_tribes_mapper_can_load_tribe(session):
+    session.execute(
+        "INSERT INTO tribes (name, level) VALUES "
+        "('tribe1', '2nd'),"
+        "('tribe2', '1ST')"
+    )
+    expected = [
+        (Tribe("tribe1", "2nd")),
+        (Tribe("tribe2", "1ST")),
+    ]
+    assert session.query(Tribe).all() == expected