`easy_install` does not support https, which has been made mandatory for
pip packages. `pip` supports it natively.

See also https://github.com/clarin-eric/SPF-SPs-metadata/pull/224

See https://issues.shibboleth.net/jira/browse/SSPCPP-714

This reverts commit 6732a4fb.

CLARIN-DSpace "cronjob" endless loop in
[entrypoint-script](https://gitlab.inf.unibz.it/commul/docker/clarin-dspace/-/blob/master/dockerfiles/commul-customization/entrypoint.sh#L20-48)
check: nobody will notice stop - ping to get notified of failure.

Address #59

Address #60

Address #60