Added Heroku app.json for one click deploys
Added Heroku app.json for one click deploys

kdzwinel/polyfill-service,kdzwinel/polyfill-service,jonathan-fielding/polyfill-service,JakeChampion/polyfill-service,mcshaz/polyfill-service,jonathan-fielding/polyfill-service,JakeChampion/polyfill-service,mcshaz/polyfill-service,kdzwinel/polyfill-service,jonathan-fielding/polyfill-service,mcshaz/polyfill-service