A handful of Uber drivers in London are now driving fully electric cars as part of a new three-month study. The San Francisco taxi-hailing company, which already has thousands of hybrid Toyota Prius cars in London, has teamed up with Nissan and Chinese car firm BYD to offer Uber drivers the chance to rent Nissan Leaf vehicles or BYD 6 vehicles at “great rates.” Uber said it expects to have more than 50 fully rechargeable Nissan…