Zeppelin Cron Execution omits groups of the cronExecutionUser

Following scenario is not supported yet:

• interpreter permissions have been set only for groups (e.g. DepartmentA should be allowed to run spark interpreter)
• user creates note with %spark interpreter and schedules a cron
• now when cron runs, only username is added to authentication info. groups of the user (e.g. DepartmentA in that example) are omitted and the notebook fails with an error, that user 'xyz' has no permission for running the interpreter.