Has a Trinity College Dublin economics graduate made so much money from a meme cryptocurrency called Dogecoin that he has been able to quit his job in Goldman Sachs?  Well, that’s the rumour going viral about Aziz McMahon, a 14-year veteran with Goldman, who was until recently a managing director in its emerging markets division.  Since rumours of McMahon’s fortune from trading Dogecoin began on Monday the story has been picked up on over 1,000 sites on the internet and been carried in publications like Business Insider as well as hundreds of more esoteric crypto websites.  Yesterday, Joe Weisenthal, an…