With more snow on the way this weekend, the city of Somerville is partnering with a young start up duo to look out for roof collapses. Jovan Tanasijevic and Emilie Pickering founded Above Summit about a year ago. It’s a video production based in Somerville that specializes in using drone technology for aerial shots. Now they’re spending the week flying drones over public buildings to check for snow drifts, ice, and potential roof collapses. “We’ve gotten more involved with the city. It’s exciting, especially in an emergency situation like this,” Pickering said.