fix(plain css): Due to the odd nature of 'glob', you can't have a set…

… of just one item.

so adding an extra ',' at the end so that you will always have at least two "items" in the set

Closes #178, #204

index.js

@@ -13,7 +13,7 @@ module.exports = {
     return new Funnel(this.projectRoot, {
       srcDir: this._podDirectory(),
       exclude: ['styles/**/*'],
-      include: ['**/*.{' + this.allowedStyleExtensions + '}'],
+      include: ['**/*.{' + this.allowedStyleExtensions + ',}'],
       allowEmpty: true,
       annotation: 'Funnel (ember-component-css grab files)'
     });