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

Update ember to latest 3.x patch

addons/api/tests/index.html

@@ -28,7 +28,7 @@
       </div>
     </div>
 
-    <script src="/testem.js" integrity=""></script>
+    <script src="/testem.js" integrity="" data-embroider-ignore></script>
     <script src="{{rootURL}}assets/vendor.js"></script>
     <script src="{{rootURL}}assets/test-support.js"></script>
     <script src="{{rootURL}}assets/dummy.js"></script>