Description of problem:
To create a cluster on ipv6 nodes two additional steps need to be added to the section 3.2.2. Configuring Ceph Global Settings.
1) After step 9,
A step must be added to set 'ip_version' to ipv6
2) After step 11,
A step must be added to set 'radosgw_civetweb_bind_ip' to 'ansible_default_ipv6.address'
These steps can be added with a note saying 'Only if using ipv6 configured nodes'
These additional steps are discussed in BZ 1416010