chore(testing): Remove reference to PreviewProvider.jsm (#2994)
chore(testing): Remove reference to PreviewProvider.jsm (#2994)


mozilla/activity-stream,mozilla/activity-stream,rlr/activity-streams,mozilla/activity-streams,Mardak/activity-stream,Mardak/activity-stream,sarracini/activity-stream,mozilla/activity-stream,sarracini/activity-stream,mozilla/activity-stream,mozilla/activity-streams,AdamHillier/activity-stream,rlr/activity-streams,AdamHillier/activity-stream,JaredKerim-Mozilla/activity-stream,rlr/activity-streams,AdamHillier/activity-stream,JaredKerim-Mozilla/activity-stream,AdamHillier/activity-stream,rlr/activity-streams,Mardak/activity-stream,Mardak/activity-stream,sarracini/activity-stream,JaredKerim-Mozilla/activity-stream,sarracini/activity-stream,JaredKerim-Mozilla/activity-stream