Add rolling update defaults to all services

[BretFisher]

Many of the services, especially for the demo apps like menu, ghost, and voting should have custom deploy settings for updates, such as rollback, healthchecks, etc. This first requires healthchecks everywhere:

• add healthchecks to each service that needs HA rolling updates
• update stack files with update settings needed for auto rollback, etc.

[pascalandy]

Glad to see that this project is still under your radar. Thanks for sharing!

[pascalandy]

I'm not sure about the specs you have in mind but shepherd is a sidecar that automatically updates docker services. It's similar to watchtower (for docker run stuff ). I use it in my stacks and it works well :)

[BretFisher]

Thanks for the plug. Auto-service-update automation/webhooks would be its own Issue. This one is about adding options to stacks for updates/rollbacks/healthchecks for every app.