Docker image generation for ledger-on-bifrost application

[sync-by-unito]

Summary

Automated integration testing and deployment would benefit from having Docker images automatically generated from the CI for every PR and release. A Github Actions workflow should be added to the project to push a new Docker image to Docker Hub and the Github Container Registry.

Acceptance criteria

• A new snapshot is pushed for every successful merge into dev
• A new release is pushed for every tag

┆Issue is synchronized with this Jira Task by Unito