Update .travis.yml with xcffib and cairocffi
Update .travis.yml with xcffib and cairocffi

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