qunit-dom: Add missing setup() call

Author: Turbo87

tests/test-helper.js

@@ -1,9 +1,14 @@
 import { setApplication } from '@ember/test-helpers';
 import start from 'ember-exam/test-support/start';
+import * as QUnit from 'qunit';
+
+import { setup } from 'qunit-dom';
 
 import Application from '../app';
 import config from '../config/environment';
 
+setup(QUnit.assert);
+
 setApplication(Application.create(config.APP));
 
 start();