Update Ember CLI add-on package definition

> ember server                                                                                               
version: 0.0.40
DEPRECATION: torii is using the deprecated ember-addon-main definition. It should be updated to {'ember-addon': {'main': 'ember-addon/index.js'}}
DEPRECATION: torii is using the deprecated ember-addon-main definition. It should be updated to {'ember-addon': {'main': 'ember-addon/index.js'}}
DEPRECATION: torii is using the deprecated ember-addon-main definition. It should be updated to {'ember-addon': {'main': 'ember-addon/index.js'}}