Fix build

Author: surma

elements/howto-menu-button/README.md

@@ -0,0 +1,4 @@
+A menu button is a button that opens a menu.
+It is referenced by the menu using aria-labelledby attribute.
+
+See: https://www.w3.org/TR/wai-aria-practices-1.1/#menubutton

elements/howto-menu-button/howto-menu-button.e2etest.js

@@ -7,7 +7,7 @@ describe('howto-menu-button', function() {
   let driver;
   beforeEach(function() {
     driver = this.driver;
-    return this.driver.get(`${this.address}/howto-menu-button_demo.html`)
+    return this.driver.get(`${this.address}/howto-menu-button/demo.html`)
       .then(_ => helper.waitForElement(this.driver, 'howto-menu-button'));
   });
 

elements/howto-menu-button/howto-menu-button.js

@@ -1,9 +1,3 @@
-/*
- * A menu button is a button that opens a menu.
- * It is referenced by the menu using aria-labelledby attribute.
- *
- * See: https://www.w3.org/TR/wai-aria-practices-1.1/#menubutton
- */
 (function() {
   /**
    * Define key codes to help with handling keyboard events.