Add ember-source to the "after" section of package.json
Add ember-source to the "after" section of package.json

Fixes #121

All the built-in blueprints will be provided by the `ember-source` addon in the future, so we need to make sure our blueprints come after (and override) these.

kimroen/ember-cli-coffeescript,kimroen/ember-cli-coffeescript,kimroen/ember-cli-coffeescript