fix docker compose

docker-compose.test.yml

@@ -53,6 +53,10 @@ services:
     volumes:
       - /srv/APIKEY.txt:/opt/etherpad-lite/APIKEY.txt
 #     - ./deployment/mysql.cnf:/etc/mysql/conf.d
+    healthcheck:
+      test: curl --fail http://localhost:9001 || exit 1
+      timeout: 20s
+      retries: 20
   fet2020:
     image: docker.fet.at/fet2020django
     container_name: test_fet2020