upgraded to Ember.js 1.4.0

1.4.0 includes the following deprecation message:

DEPRECATION: Using a quoteless parameter with {{render}} is deprecated. Please update to quoted usage '{{render "navbar"}}.

I've obliged, updating this non-quoted usage of the {{render}} helper. (It was the only such usage.)

https://github.com/askcom/quarry-webui/issues/1