Updated page revisions link visibility

To match the actual visibilities of the revisions listing page and
options.
Related to #2946

tests/TestCase.php

@@ -89,6 +89,14 @@ abstract class TestCase extends BaseTestCase
         return $this->editor;
     }
 
+    /**
+     * Set the current user context to be a viewer.
+     */
+    public function asViewer()
+    {
+        return $this->actingAs($this->getViewer());
+    }
+
     /**
      * Get an instance of a user with 'viewer' permissions.
      */