Investigate replacing Roxy with ml-app-deployer CLI

[grtjn]

Internal teams have shifted focus away from Roxy in favor of ml-gradle, and ml-app-deployer that is behind ml-gradle. Roxy is not using management rest api. We (the Roxy dev team) have long pondered moving over, but lingered too long to be able to make it happen. It kind of forces us now to move on, and migrate to something else. I managed to convince one of the core developers of ml-gradle to expose a CLI for ml-app-deployer, making it easier to use the core features of ml-gradle without needing Gradle itself. Lets investigate the impact..