Swiss postal service says tests will run until the end of July although the widespread use of drones is not likely to kick in for another five yearsSwitzerland’s postal service said on Tuesday it had begun testing parcel deliveries by unmanned drones, although widespread use of the flying postmen is not likely to kick in for another five years.Postal service executives showed off the drones for the first time on Tuesday and said initial tests of the machines’ post-delivery abilities would run until the end of July.