Set mysql root PW to randomize

docker-compose.yml

@@ -5,7 +5,7 @@ services:
     image: mysql
     restart: always
     environment:
-      MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD}
+      MYSQL_RANDOM_ROOT_PASSWORD: 'true'
       MYSQL_USER: ${MYSQL_USER}
       MYSQL_PASSWORD: ${MYSQL_PASSWORD}
       MYSQL_DATABASE: ${MYSQL_DATABASE}