Add new Dockerfile for prod

docker-compose.yml

@@ -3,6 +3,8 @@ version: '3'
 services:
   db:
     image: postgres
+    volumes:
+      - db-data:/var/lib/postgresql/data
   web:
     build: .
     image: registry.gitlab.com/sahkoinsinoorikilta/vtmk/web2.0-backend
@@ -11,3 +13,5 @@ services:
       - "8000:8000"
     depends_on:
       - db
+volumes:
+  db-data: {}