Update travis configuration
Update travis configuration

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

acsone/stock-logistics-workflow,brain-tec/stock-logistics-workflow,akretion/stock-logistics-workflow,xpansa/stock-logistics-workflow,open-synergy/stock-logistics-workflow,BT-jmichaud/stock-logistics-workflow,Eficent/stock-logistics-workflow,archetipo/stock-logistics-workflow,gurneyalex/stock-logistics-workflow,akretion/stock-logistics-workflow,BT-fgarbely/stock-logistics-workflow,Antiun/stock-logistics-workflow,vrenaville/stock-logistics-workflow,raycarnes/stock-logistics-workflow,xpansa/stock-logistics-workflow,open-synergy/stock-logistics-workflow,gurneyalex/stock-logistics-workflow,Eficent/stock-logistics-workflow,Endika/stock-logistics-workflow,acsone/stock-logistics-workflow,brain-tec/stock-logistics-workflow