make the database persistant in production

docker-compose.prod.yml

@@ -6,6 +6,7 @@ services:
     command: gunicorn franklincce.wsgi:application --bind 0.0.0.0:8000
     volumes:
       - static_volume:/home/app/web/staticfiles
+      - db_persist:/home/app/web/franklincce/db.sqlite3
     expose:
       - 8000
     env_file:
@@ -20,3 +21,4 @@ services:
       - web
 volumes:
   static_volume:
+  db_persist: