VANCOUVER – Spurned by U.S. regulators, Amazon.com has turned to the one country where flying delivery robots are still welcome: Canada. On Monday, the U.K.’s Guardian newspaper revealed that the online retail giant is testing its latest prototypes for package-carrying drones at a top-secret site in British Columbia. “We are rapidly experimenting and iterating on Amazon Prime Air … including outdoors at a rural test site in Canada,” wrote Amazon spokesperson Kristen Kish in an email to the National Post. --- Located a mere 600 metres from the U.S. border, the Canadian testing grounds fulfill a lingering threat by Amazon...