Provide a way to remove old results of a scheduled job

[marco-c]

I'm using the results of a scheduled job on an external web page.

The results are in different files, and they don't always have the same name (that is, two job runs can generate two different set of files). So, when a new job finishes, the old results are not always overwritten.

To avoid showing stale results to users, I'd need to remove the old results before uploading the new ones. I'm currently doing that manually using boto in my notebook, but it is not a robust solution.

Another option would be to create a redirect to the results folder of the latest successful job run (once #189 is fixed).