Feedback responses page clean up and behat tests

During testing you can switch between upstream and integration branches and compare how feedback response page looks. Enable feedback module Set up mail Create feedback in the course, select to send notifications, add some questions Complete feedback as couple of students Every time the feedback is completed teacher should receive notification but the link in the notification should lead to "Show responses" page and not to a particular response As a teacher view responses list To test pagination change the constant FEEDBACK_DEFAULT_PAGE_COUNT to something smaller (or create over 20 responses) Make sure you can navigate between responses using Next/prev links make sure you can delete responses Create another feedback (or duplicate this one) and make it non-anonymous Complete it as several students Now teacher should receive email with the student name and the link to a particular response As a teacher browse "Show responses", view responses list, one by one, sort or filter table, etc Make sure pagination and "Show all" link work Make sure you can navigate between responses using Next/prev links Make sure you can delete individual responses