Fix "latest" to point to 2.1 instead of 2.0
Fix "latest" to point to 2.1 instead of 2.0

cgvarela/docker-iojs,nodejs/docker-iojs,hmalphettes/docker-iojs,bnadim/docker-iojs,infosiftr/docker-iojs,jbhannah/docker-iojs,yyolk/docker-iojs-graphicsmagick,pesho/docker-iojs