kpasswd is the client for changing passwords.
If administrator principal is given that principal is used to change the password.
Multiple passwords for different users can be changed at the same time, then the administrator principal
will be used. If the administrator isn't specified on the command prompt, the principal of the default
credential cache will be used.
If a credential cache is given, the --admin-principal flag is ignored and use the default name of the
credential cache is used instead.