Add volume (bind mount) for tmp directory

tmp directory will be created on the host
you might need to adjust permissions of this directory
otherwise the playground user inside the container
won't be allowed to write to the tmp directory

As a workaround for #158
Remove tmp files using cron

Author: Phu2

docker-compose.yml

@@ -12,6 +12,7 @@ services:
     volumes:
       - '/etc/timezone:/etc/timezone:ro' # Sync with host
       - '/etc/localtime:/etc/localtime:ro' # Sync with host
+      - './tmp:/home/playground/metafacture-playground/tmp'
     deploy:
       resources:
         limits: