Use DB_PASS for root and regular password

docker-compose.yml

@@ -9,10 +9,14 @@ services:
       - /var/log/cpolis.log:/var/log/cpolis.log
     depends_on:
       - db
+    environment:
+      DB_USER: cpolis
+      DB_PASS: ${DB_PASS}
 
   db:
     image: mariadb:latest
     environment:
+      MYSQL_ROOT_PASSWORD: ${DB_PASS}
       MYSQL_DATABASE: cpolis
       MYSQL_USER: cpolis
       MYSQL_PASSWORD: ${DB_PASS}