Patrick Frater Asia Bureau ChiefBeijing- and Amsterdam-based sales agency Fortissimo Films has added to its Cannes slate feature-length Chinese documentary “Keep Running.” It will be first pitched to distributors during the Cannes Market.The picture tracks a team of teenagers form underprivileged backgrounds who live in Gen He, the coldest part of China, and run every day despite the harsh circumstances.It is the first full-length picture directed by Sun Getting, who previously made TV series