Rollan Mattson didn’t expect to make history when he lined up for Siena Heights University’s commencement on Saturday. But about three hours in, the 22-year-old nursing major walked across the school’s fieldhouse stage with a rare distinction: He was the final graduate of the 107-year-old private Catholic university, which is closing its doors for good . Siena Heights, founded by the Adrian Dominican Sisters in 1919, is the latest in a wave of smaller private and faith-based colleges to close