Cuba is often derided, appropriately, as a backwards nation that has failed to modernize its houses, cars and overall economic policies. I got to visit its capital city of Havana this summer, and found this perception evident from the moment I stepped into José Martí airport. But there was one aspect of Havana that felt futuristic: the city’s mass carpooling system. For ridesharing companies in the U.S. that are looking to grow their carpooling offshoots–including Uber…