Simple update of the heroku sample URL in the readme.
Simple update of the heroku sample URL in the readme.

Since it's suggested to use Cedar in the instructions, this updates the sample heroku URL to use the "herokuapp.com" domain.
evaautomation/janky,eLobato/janky,dLobatog/janky,Kast0rTr0y/janky,aergonaut/janky,eLobato/janky,digideskio/janky,mattclark/janky,cnbin/janky,fgbreel/janky,evaautomation/janky,dLobatog/janky,netflower/janky,mattclark/janky,evaautomation/janky,github/janky,netflower/janky,OSS-TheWeatherCompany/janky,cnbin/janky,mullingitover/janky,mal/janky,Kast0rTr0y/janky,github/janky,plataformatec/janky,mattclark/janky,cnbin/janky,TheWeatherCompany/janky,digideskio/janky,fgbreel/janky,mal/janky,mullingitover/janky,dLobatog/janky,aergonaut/janky,dLobatog/janky,TheWeatherCompany/janky,mullingitover/janky,eLobato/janky,fgbreel/janky,Kast0rTr0y/janky,OSS-TheWeatherCompany/janky,cnbin/janky,aergonaut/janky,netflower/janky,mattclark/janky,TheWeatherCompany/janky,netflower/janky,mullingitover/janky,plataformatec/janky,digideskio/janky,evaautomation/janky,Kast0rTr0y/janky,github/janky,fgbreel/janky,digideskio/janky,eLobato/janky,aergonaut/janky,plataformatec/janky,TheWeatherCompany/janky,OSS-TheWeatherCompany/janky,OSS-TheWeatherCompany/janky,plataformatec/janky,mal/janky