Update travis configuration
Update travis configuration

use sudo: false to enable container build
use cache: pip to cache pip packages

incaser/bank-payment,CompassionCH/bank-payment,David-Amaro/bank-payment,David-Amaro/bank-payment,Antiun/bank-payment,hbrunn/bank-payment,CompassionCH/bank-payment,ndtran/bank-payment,open-synergy/bank-payment,damdam-s/bank-payment,ndtran/bank-payment,acsone/bank-payment,Antiun/bank-payment,syci/bank-payment,diagramsoftware/bank-payment,syci/bank-payment,sergiocorato/bank-payment,sergiocorato/bank-payment,damdam-s/bank-payment