Update modules
Remove reference to js/config.js
Update Ember and QUnit
Remove custom error handler for gulp-plumber

The default one is much better now.
Alphabetize dependencies
Use yargs for command line arguments
Use gulp-if for conditional piping
Remove gulp-util
Get AMD module loader and resolver from Bower
Replace gulp-ember-handlebars; use modules for templates

gulp-ember-handlebars is deprecated