Make SkyElement more classy.

sky/examples/flights-app/app-panel-content.sky

Index: sky/examples/flights-app/app-panel-content.sky
diff --git a/sky/examples/flights-app/app-panel-content.sky b/sky/examples/flights-app/app-panel-content.sky
index 9bc9330955997988a178081b42bde3cdf4f73670..8d96c9aae6d7b6ad1fecef82fac0250d39ebf210 100644
--- a/sky/examples/flights-app/app-panel-content.sky
+++ b/sky/examples/flights-app/app-panel-content.sky
@@ -1,4 +1,6 @@
 <import src="../../framework/sky-element/sky-element.sky" as="SkyElement" />
+
+<sky-element name="app-panel-content">
 <template>
   <style>
     :host {
@@ -8,7 +10,7 @@
   <content></content>
 </template>
 <script>
-SkyElement({
-  name: "app-panel-content"
-});
+module.exports = class extends SkyElement {
+}.register();
 </script>
+</sky-element>