American Repertory Theater (A.R.T.) at Harvard University's production of Two Strangers (Carry a Cake Across New York) begins performances tonight, Tuesday, May 20, at the Loeb Drama Center in Harvard Square. Get a first look at the cast in action! The musical follows Dougal, an optimistic British man visiting New York for the wedding of a father he's never met, and Robin, the bride's sister, who's reluctantly tasked…