created initial sql engine

dg_osm/db/engine.py

@@ -0,0 +1,7 @@
+import os
+
+from sqlalchemy import create_engine
+
+current_path = os.path.dirname(os.path.abspath(__file__))
+database_url = f'sqlite:///{current_path}data/dg_osm.db'
+engine = create_engine(database_url, echo=True)