Ember index.html asset files don't get appended with hash

I deployed my Ember app to S3 using this tutorial: http://ift.tt/2qr68mo

My asset filenames get appended with a hash, but the index.html still references the original filename with the hash, so it fails to load the assets. After reading around, I believe my index.html file is supposed to get updated with new filenames, but not sure why that is not happening.