travis: Add packagekitglib as necessary package
travis: Add packagekitglib as necessary package

vignanl/Plinth,kkampardi/Plinth,jvalleroy/plinth-debian,freedomboxtwh/Plinth,freedomboxtwh/Plinth,vignanl/Plinth,harry-7/Plinth,freedomboxtwh/Plinth,kkampardi/Plinth,jvalleroy/plinth-debian,kkampardi/Plinth,jvalleroy/plinth-debian,freedomboxtwh/Plinth,vignanl/Plinth,harry-7/Plinth,kkampardi/Plinth,harry-7/Plinth,vignanl/Plinth,freedomboxtwh/Plinth,vignanl/Plinth,harry-7/Plinth,jvalleroy/plinth-debian,harry-7/Plinth,kkampardi/Plinth,jvalleroy/plinth-debian