Extract AwsRegistry into its own file; retrofit spec
Avoid passing around instance state
Extract LightStemcell class from Ami
Shrink publish_ami.rb since it isn't run locally
Replace spec/publish_ami.rb with a rake task
Stop creating unused stemcell-ami.txt
Simplify light stemcell creation
Extract "publish to pipeline" to reuse for light stemcell
Internalize param that never changes and rename method