Code review comment for lp:~viswesn/juju-ci-tools/ensure_provider_cleanup

This branch is created long back for juju-ci-cleanup enhancement work and already we integrated the changes specific to most of the cloud providers and that is the reason for seeing code changes for providers like OpenStack, GCE, etc. As discussed in the call today I kept changes only for AWS and other provider changes were removed.

Please review it and let me know your comments on the updated code base. Thanks