By Dan Marsh Arsenal prodigy Chido Obi-Martin bagged another remarkable goal haul by scoring SEVEN in the Under-18’s 9-0 win over Norwich City on Saturday afternoon. The highly-rated 16-year-old made headlines earlier in the season after scoring 10 goals in a single match for Arsenal’s Under-16 side against Liverpool. And he’s continued in that rich vein of form ever since with impressive hauls for the U18s against Southampton and Crystal Palace. Obi-Martin was at it again on Saturday when he lined up for Arsenal’s academy against the Canaries, plundering seven goals in just over an hour in th…