Update travis configuration
Update travis configuration

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

lepistone/runbot-addons,open-synergy/runbot-addons,ndp-systemes/runbot-addons,Niboo/runbot-addons,depfac/runbot-addons,samuellefever/runbot-addons,jose-eezee/runbot-addons,eezee-it/runbot-addons