Use feed role for notifs and timelines

src/components/notifications/notifications.vue

@@ -52,7 +52,7 @@
         </div>
         <div
           class="panel-body"
-          role="list"
+          role="feed"
         >
           <div
             v-for="notification in notificationsToDisplay"

src/components/timeline/timeline.vue

@@ -79,7 +79,7 @@
       <div
         ref="timeline"
         class="timeline"
-        role="list"
+        role="feed"
       >
         <conversation
           v-for="statusId in filteredPinnedStatusIds"