Handle E2E tests on real devices

Hi there, it might be great if this (already useful) example could be completed with an example of E2E tests on real devices. I am trying to do that with Appium but it fails for the moment, I submitted an issue, [here](https://github.com/appium/appium/issues/8351), in the [Appium](https://github.com/appium/appium) repository concerning the troubles that I am facing, trying to extend this Ionic Unit Testing Example.

Maybe someone already tried this and/or faced this issue?