add getGroup method
We can run this method as: ./perun_cli.py --instance einfra_acc --http-basic-auth --kerberos --user cloud_service --password [PASS] getGroup --group_id 15127
Edited by Josef Němec
We can run this method as: ./perun_cli.py --instance einfra_acc --http-basic-auth --kerberos --user cloud_service --password [PASS] getGroup --group_id 15127