Chore/parallelize tests (#1556)

addons/api/tests/test-helper.js

@@ -3,7 +3,7 @@ import config from 'dummy/config/environment';
 import * as QUnit from 'qunit';
 import { setApplication } from '@ember/test-helpers';
 import { setup } from 'qunit-dom';
-import { start } from 'ember-qunit';
+import start from 'ember-exam/test-support/start';
 
 setApplication(Application.create(config.APP));