Non-root directory Ionic project possible?

Question about directory structure for ionic1 deploy. Our repo is structured like this

 mobile/ # the ionic1 project
 …config files, etc

Is there a way to let Ionic deploy/build processes know to look at mobile/ rather than root/? Maybe an undocumented root/.ionicrc or some prop in root/ionic.config.json? (edited)

Looks like could help, but simply including config: {ionic_root_dir: "mobile"} in package.json doesn’t work.