Amazon.com union members at another U.S. facility voted to authorize a strike, becoming the third to do so in less than a week as tensions with the e-commerce giant expand across the country over contract negotiations. Teamsters, one of America’s largest labor unions, on Monday said that workers at the DIL7 Amazon delivery station in Skokie, Ill., voted overwhelmingly in favor of the move, joining workers of New York City’s Staten Island JFK8 and Queens DBK4 facilities, which last Friday made public they had authorized strikes of their own. The union had given Amazon a Dec. 15 deadline to agree to come to the table and bargain for a contract.