Chore update ember to latest 3.x (#1409)

Update ember to latest 3.x patch

addons/core/ember-cli-build.js

@@ -1,6 +1,7 @@
 'use strict';
 
 const EmberAddon = require('ember-cli/lib/broccoli/ember-addon');
+const { maybeEmbroider } = require('@embroider/test-setup');
 
 module.exports = function (defaults) {
   let app = new EmberAddon(defaults, {
@@ -17,5 +18,11 @@ module.exports = function (defaults) {
     behave. You most likely want to be modifying `./index.js` or app's build file
   */
 
-  return app.toTree();
+  return maybeEmbroider(app, {
+    skipBabel: [
+      {
+        package: 'qunit',
+      },
+    ],
+  });
 };