tweaking dependencies / peerDependencies

as seen in angularfire: https://github.com/angular/angularfire/blob/2ce41aa0af8c5f42df65f5ac5b2b5a50fb6f4300/package.json#L41-L68

commander has some breaking changes, so let's risk nothing here and rollback

Author: JohannesHoppe