Bitcoin is no long the only game in crypto-currency town IT STARTED as a joke. Dogecoin was launched in 2013 as a bitcoin parody, using as its mascot a Japanese shiba inu dog, a popular internet meme. The crypto-currency was never really used, except for tipping online, and one of its founders has called it quits. But recently its price has soared: on January 7th the dollar value of all Dogecoins in circulation reached $2bn, a sign of how crazy…