Since Ember.CollectionView is a subclass of Ember.ContainerView, it does not have a template of its own.
From the API docs:
A template, templateName, defaultTemplate, layout, layoutName or defaultLayout property on a container view will not result in the template or layout being rendered. The HTML contents of a Ember.ContainerView's DOM representation will only be the rendered HTML of its child views.
To make this work you can move the collection_template
markup into application template or make it a partial. Then replace {{outlet}}
with {{collection App.CollectionViewTest}}