Prevent crash on views with no controller

I found a case where ember can generate views with no controller. Eg. a simple "loading" view while starting the app. This caused ember-inspector to crash.

I have fixed the issue by adding support for any view with no controller.
@teddyzeenny Sure. Wasn't sure about that one. Is it possible for component to have a controller, or we just playing it safe? All the tests passed as it is.