Fix swapped volume_up_command and volume_down_command in the Volume widget.
Fix swapped volume_up_command and volume_down_command in the Volume widget.

Closes #484

w1ndy/qtile,StephenBarnes/qtile,EndPointCorp/qtile,apinsard/qtile,zordsdavini/qtile,xplv/qtile,kiniou/qtile,encukou/qtile,qtile/qtile,StephenBarnes/qtile,w1ndy/qtile,ramnes/qtile,cortesi/qtile,himaaaatti/qtile,kiniou/qtile,kseistrup/qtile,encukou/qtile,flacjacket/qtile,dequis/qtile,de-vri-es/qtile,farebord/qtile,andrewyoung1991/qtile,himaaaatti/qtile,ramnes/qtile,zordsdavini/qtile,EndPointCorp/qtile,rxcomm/qtile,kopchik/qtile,soulchainer/qtile,soulchainer/qtile,kynikos/qtile,frostidaho/qtile,andrewyoung1991/qtile,xplv/qtile,jdowner/qtile,tych0/qtile,de-vri-es/qtile,rxcomm/qtile,cortesi/qtile,kseistrup/qtile,farebord/qtile,nxnfufunezn/qtile,frostidaho/qtile,aniruddhkanojia/qtile,aniruddhkanojia/qtile,apinsard/qtile,dequis/qtile,qtile/qtile,kopchik/qtile,flacjacket/qtile,nxnfufunezn/qtile,jdowner/qtile,tych0/qtile,kynikos/qtile