Added correct Heroku url
Added correct Heroku url

All Heroku applications are hosted under `herokuapp` domain so each of them looks like `app-name.herokuapp.com`. [heroku.com](http://heroku.com/) is only for accessing a dashboard and no user apps are hosted as its subdomain.
tokafish/phoenix_guides,evax/phoenix,optikfluffel/phoenix,pap/phoenix,mitchellhenke/phoenix,eksperimental/phoenix,optikfluffel/phoenix,3quarterstack/phoenix_guides,jwarwick/phoenix,dmarkow/phoenix,mschae/phoenix,korobkov/phoenix,keathley/phoenix,Joe-noh/phoenix,bsmr-erlang/phoenix,mitchellhenke/phoenix,tianyi33/phoenix_guides,rafbgarcia/phoenix,bratsche/phoenix_guides,mobileoverlord/phoenix,fblecha/phoenix_guides,gjaldon/phoenix,phoenixframework/phoenix,trarbr/phoenix,michalmuskala/phoenix,pap/phoenix-guides,bsmr-erlang/phoenix,evax/phoenix,phoenixframework/phoenix,Joe-noh/phoenix,mobileoverlord/phoenix,nshafer/phoenix,jwarwick/phoenix,nshafer/phoenix,rafbgarcia/phoenix,mschae/phoenix,wsmoak/phoenix_guides,Kosmas/phoenix,rafbgarcia/phoenix,Gazler/phoenix,gjaldon/phoenix,jeffkreeftmeijer/phoenix_guides,0x00evil/phoenix,stevedomin/phoenix,dmarkow/phoenix,nshafer/phoenix,Gazler/phoenix,pap/phoenix,eksperimental/phoenix,optikfluffel/phoenix,phoenixframework/phoenix,0x00evil/phoenix,korobkov/phoenix,trarbr/phoenix,0x00evil/phoenix,stevedomin/phoenix,michalmuskala/phoenix,keathley/phoenix,Kosmas/phoenix