Wait until Minio is ready before creating buckets

Using a while loop and curl to get Minio root URL.

docker-compose.yml

@@ -46,6 +46,7 @@ services:
     env_file: .env
     entrypoint: >
       /bin/sh -c "
+      while ! curl -s --output /dev/null --connect-timeout 1 http://minio:9000; do echo 'Waiting minio...' && sleep 0.1; done;
       /usr/bin/mc alias set minio http://minio:9000 $MINIO_ROOT_USER $MINIO_ROOT_PASSWORD;
       /usr/bin/mc mb minio/attachments;
       /usr/bin/mc mb minio/avatars;