Docs for skipping user creation w/LDAP
Docs for skipping user creation w/LDAP

Change-Id: I5316432bf96124d5c4022a367a8684a4320a68f3
(cherry picked from commit 1d13b9775c2c3fb0c7b2efb671acffd00f1700aa)

yanyao/openstack-deployment,VaneCloud/openstack-ansible,VaneCloud/openstack-ansible,VaneCloud/openstack-ansible,yanyao/openstack-deployment,yanyao/openstack-deployment,yanyao/openstack-deployment