Fix docs about --is-public parameter for glance image-create
Fix docs about --is-public parameter for glance image-create

The glance CLI now defaults to the v2 API which has a non-binary
visibility field, therefor the "--is-public" parameter has been removed
and "--visibility public/private" should be used instead (Note: the
--container-format parameter is required now as well).

Closes-Bug: #1494807
Change-Id: I7d0c9d8cfce3e799bd7d5c4eedc393a8fc7c94be

bacaldwell/ironic,pshchelo/ironic,naterh/ironic,SauloAislan/ironic,dims/ironic,hpproliant/ironic,ionutbalutoiu/ironic,openstack/ironic,ionutbalutoiu/ironic,pshchelo/ironic,NaohiroTamura/ironic,SauloAislan/ironic,NaohiroTamura/ironic,openstack/ironic,redhat-openstack/ironic,dims/ironic,devananda/ironic,bacaldwell/ironic