stack update
- Pass SSH keys in, using support added in 18.09
- Create SSH agent in pipeline
- Correctly push to Gitlab
- Use standardized pipeline
- Use new storable-18 stack image as base
- Import !24 (merged)
- Add health Procfile entry if it doesn't exist
- Add HEALTHCHECK for health Procfile entry
- Upgrade to docker 20
- Use ECR location for stack image