remove end tag for <input>

<input> shouldn't have an explicit end tag

demo.html

@@ -89,7 +89,7 @@ <h2>Dialog</h2>
 			<div>Ut aliquam vulputate congue. Vestibulum pretium pretium nulla quis sollicitudin. Praesent lacinia congue erat nec mattis. Fusce commodo lacus est. Duis turpis eros, ultrices sed aliquet non, blandit egestas velit. Integer a augue nec lorem tristique hendrerit. Curabitur imperdiet risus id enim bibendum vestibulum. Integer id magna at arcu faucibus fermentum vel a augue. Sed fringilla venenatis dolor, in blandit magna molestie luctus. Vestibulum dignissim posuere ultrices. Aenean urna nisl, tincidunt vitae iaculis ut, pharetra nec eros.</div><br><br>
 
 			<div>
-				<input placeholder="say something..." autofocus on-input="{{inputHandler}}"></input><br>
+				<input placeholder="say something..." autofocus on-input="{{inputHandler}}" /><br>
 				I agree with this wholeheartedly.
 				<core-overlay layered id="confirmation" class="dialog" backdrop transition="core-transition-top">
 					<!-- place all overlay styles inside the overlay target -->