Danish-born Nigerian young forward Chidozie Martin-Obi scored seven goals for Arsenal’s U-18s in their 9-0 win against Norwich on Saturday. The 16-year-old netted a hat-trick in 17 minutes before adding two more goals, to end the first half of the U-18 Premier League game with five goals. He then got on the score sheet two times in the second half. Martin-Obi got his side to the perfect start…