It could be handy to have a testing framework in the spirit of [cst](https://github.com/GoogleContainerTools/container-structure-test), that is auto-executed after a `pack` is complete, similar to `health-check` in [multipass blueprints](https://github.com/canonical/multipass-blueprints/blob/6a46d02e2db095c8e738f44c18584b4c96dc2e29/v1/docker.yaml#L146).