bump sidekiq to 3.5.4
bump sidekiq to 3.5.4

mkcode/classroom,hackerkid/classroom,jasnow/classroom,BelieveC/classroom,mkcode/classroom,BelieveC/classroom,ConnorCartwright/classroom,BelieveC/classroom,jasnow/classroom,hackerkid/classroom,hackerkid/classroom,ConnorCartwright/classroom,BelieveC/classroom,mkcode/classroom,ConnorCartwright/classroom,jasnow/classroom