CLONE - Students in a chat can send a sound to other participants

1. Login as student1 and access a chat activity.
2. Click to enter the chat.
3. In a different browser, login as student2 and access the chat.
4. Click to enter the chat then click the beep link for student1.
5. Check that a beep sound is heard and the message 'Sam has just beeped you!' is displayed for student1 (where Sam is the name of student2).

Note: On Linux, you need a browser plugin installed in order to play sound.