use new API for group administration
Currently, the CLI still uses the old API (https://iam.passwort.ethz.ch/iam-ws-legacy/groupmgr/group)
However, with the introduction of the certificationPeriod
, the creation of new groups is broken and/or leads to unexpected problems. We therfore have to switch to the new API (https://iamws.ethz.ch/groups) ASAP.