Cloned from launchpad blueprint https://blueprints.launchpad.net/heat/+spec/scaling-group-health. Description: This spec fills a major gap compared to AWS autoscaling groups: automatic maintenance of member health. This spec follows the leanness of the AWS interface design as closely as possible, diverging as required by the ways that OpenStack differs from AWS. The implementation is direct (rather than indirect through another project). Specification URL (additional information): https://review.openstack.org/#/c/110354/