From that list, at least you input:
- ADMIN EMAIL: fill with the admin email
- DOMAIN: fill with your heroku domain
- MAILER_EMAIL_ID: your account mailer
- MAILER_FROM: your account mailer
- MAILER_PASSWORD: your password
- MAILER_SERVICE_PROVIDER: your smtp service
- MONGOLAB_URI: your mongodb URI (mongodb://:@ds147872.mlab.com:47872/project-a-dev)