rm Cloud variant; mv CloudImages Cloud
    
    We need to stop building repos and install media for the *Cloud* variant
    because the only consumers of those repos/install media is the cloud
    base images that could easily be built with the Everything repo/install
    media. This commit removes the cloud variant (as it was previously
    known) and then renames the CloudImages variant to 'Cloud'.
    
    Summary:
    
    - Cloud now becomes an empty variant (no repos, no install media)
    - CloudImages variant goes away
    - Cloud image builds use Everything repo/install media
    - Atomic image builds use Everything install tree
    
    Signed-off-by: Dusty Mabe <dusty@dustymabe.com>