Clean up (Remove all completely)
Re-initialize

Run "rails new env_var_heroku"

Versions
  Ruby: 2.1.2p95
  Rails: 4.1.4
Run "rails g controller home index"
Modify the root routing
Show environment variables values
Checkout README.md from 58bc5a078775f6fe32e7a760f73381bfb426b211
Modify from "heroku config:add" to "heroku config:set"
Declare public domain