include .valid() in the .featured() query (bug 584978)

apps/addons/models.py

@@ -52,8 +52,9 @@ class AddonManager(amo.models.ManagerBase):
         Filter for all featured add-ons for an application in all locales.
         """
         today = date.today()
-        return self.filter(feature__application=app.id,
-                           feature__start__lte=today, feature__end__gte=today)
+        return self.valid().filter(feature__application=app.id,
+                                   feature__start__lte=today,
+                                   feature__end__gte=today)
 
     def category_featured(self):
         """Get all category-featured add-ons for ``app`` in all locales."""