Add app.json for Heroku Button deploys
Add Heroku Button to README for simple deploys
Update app.json with an actual repo URL. Updates #19.
Change postdeploy scripts from an array of commands to a string of && combined commands. Updates #19.
Merge pull request #20 from homesteading/app-json-19

Add app.json to repo root and Heroku Button for one click deploys. Closes #19.