Add missing comma in output text
Add missing comma in output text

Enumerations need a comma before "and".

Change-Id: I11dd74498f8eb4497bd6d896ee0e4e23e3b086ac

savinash47/openstack-doc-tools,savinash47/openstack-doc-tools,openstack/openstack-doc-tools,savinash47/openstack-doc-tools,openstack/openstack-doc-tools