Updated travis config to build assets
Updated travis config to build assets

mtekel/digitalmarketplace-supplier-frontend,alphagov/digitalmarketplace-supplier-frontend,mtekel/digitalmarketplace-supplier-frontend,alphagov/digitalmarketplace-supplier-frontend,mtekel/digitalmarketplace-supplier-frontend,alphagov/digitalmarketplace-supplier-frontend,alphagov/digitalmarketplace-supplier-frontend,mtekel/digitalmarketplace-supplier-frontend