add post install message indicating deprecation for dragonfly/rails/images
add post install message indicating deprecation for dragonfly/rails/images

quarkstudio/dragonfly,markevans/dragonfly,bsodmike/dragonfly,bobbus/dragonfly,quarkstudio/dragonfly,bsodmike/dragonfly,jeremyf/dragonfly,thomas-profitt/dragonfly,anoworl/dragonfly,jeremyf/dragonfly,thomas-profitt/dragonfly,markevans/dragonfly