ref(deisctl): purge update engine logic

This PR purges the update engine logic that won't be making it into the stable release.  We plan to continue working on this, but better to have it out of the project for stable release.

This specifically removes:

 * `deisctl update` command (fixes #2298)
 * `Dockerfile` used for building a specialized `deisctl` Linux binary used for updates
 *  `lock`, `update` and `constants` packages which are only used by the update engine
 * bulk of the `utils` package