Merge pull request #3 from lyft/LYFT-14491-resolve-boto-asg-exists-issue

LYFT-14491 - resolve issue with boto_asg.exists
LYFT-14491 - make image-id required
Merge pull request #14406 from lyft/LYFT-14491-boto-asg-create-lc-image-id-required

boto_asg - create_launch_configuration - image id required