calamari-ctl: add ability to enable/disable users

Signed-off-by: Gregory Meno <gmeno@redhat.com>
docs: add enable/disable user and update username argument

Signed-off-by: Gregory Meno <gmeno@redhat.com>
tests: change invocations of calamari-ctl to remove --username

Signed-off-by: Gregory Meno <gmeno@redhat.com>
Merge pull request #240 from ceph/wip-10075

Wip 10075