Followup fix to the tests

Ref https://github.com/PolymerElements/polymer-starter-kit/pull/81
Ref a87c51aa28 (commitcomment-11444276)

app/test/my-greeting-basic.html

@@ -41,7 +41,7 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
         greeting = fixture('basic');
       });
 
-      test('Welcome, Welcome!', function() {
+      test('Welcome!', function() {
         header = greeting.querySelector('h1');
         assert.equal(header.textContent, 'Welcome!');
       });