MDL-55074 theme_boost: Phantomjs robustness

Raj was seeing some fails with phantomjs because the action menus were not open after clicking
on the link to open them. Make sure we look for the open menu before continuing.

theme/boost/tests/behat/behat_theme_boost_behat_course.php

@@ -58,6 +58,7 @@ class behat_theme_boost_behat_course extends behat_course {
             array("a[data-toggle='dropdown']", "css_element", $this->escape($activityname))
         );
 
+        $this->actions_menu_should_be_open($activityname);
     }
 
     public function i_close_actions_menu($activityname) {