Merge pull request #97 from embroider-build/use-virtual-instead-of-core

Use @embroider/virtual instead of @embroider/core

files-override/js/tests/index.html

@@ -26,7 +26,7 @@
 
     <script src="/testem.js" integrity="" data-embroider-ignore></script>
     <script src="/@embroider/virtual/vendor.js"></script>
-    <script src="/@embroider/core/test-support.js"></script>
+    <script src="/@embroider/virtual/test-support.js"></script>
     <script type="module">import "ember-testing";</script>
 
     <script type="module">