Add CentOS-6.6 cloud image
Add CentOS-6.6 cloud image

Change-Id: Ia71b3fe19bbbbe54fbba8e71d76425adf5e49549

crobby/sahara-image-elements,crobby/sahara-image-elements,openstack/sahara-image-elements,bigfootproject/sahara-image-elements,openstack/sahara-image-elements,uladz/sahara-image-elements,bigfootproject/sahara-image-elements,uladz/sahara-image-elements