RegistryProxyMixin#unregister()

Unregister a factory.

let App = Ember.Application.create();
let User = Ember.Object.extend();
App.register('model:user', User);

App.resolveRegistration('model:user').create() instanceof User //=> true

App.unregister('model:user')
App.resolveRegistration('model:user') === undefined //=> true