fix test failure caused by clearing cache

test/generator/component-ref/Widget.html

@@ -1 +1,9 @@
 <p>i am a widget</p>
+
+<script>
+	export default {
+		onrender () {
+			this.isWidget = true;
+		}
+	};
+</script>

test/generator/component-ref/_config.js

@@ -1,9 +1,7 @@
-import Widget from './Widget.html';
-
 export default {
 	html: '<div><p>i am a widget</p></div>',
 	test ( assert, component ) {
 		const widget = component.refs.widget;
-		assert.ok( widget instanceof Widget );
+		assert.ok( widget.isWidget );
 	}
 };