Despite no mandate from the federal government, airlines continue to get tougher with their face mask requirements this summer, with Alaska Airlines, JetBlue and Spirit Airlines among the carriers adopting a new policy of no mask, no travel, no exceptions moving forward.Effective Friday, all Alaska passengers age 2 and older will be required to wear a cloth mask or an approved face covering over both their nose and mouth. Those travelers who are unwilling or unable to cover up will not be allowed to travel, regardless of the reason.Meanwhile, Spirit’s requirement that customers with the except…