This is minimum Twitter bot which works on Heroku.
$ heroku create --stack cedar
$ git push heroku master
$ heroku config:set CONSUMER_KEY=your_cosumer_key CONSUMER_SECRET=your_consumer_secret ACCESS_TOKEN_KEY=your_access_token_key ACCESS_TOKEN_SECRET=your_access_token_secret
$ heroku addons:create scheduler:standard
$ heroku addons:open schedulerk
Add scheduler task.