ruby on rails - Heroku open gives a 404 -

i'm deploying rails on heroku first time, accept i'm bit of newbie on turf.

i installed tool heroku tool belt. created simple rails application. logged heroku. did..

heroku create 

and pushed master

git push heroku master 

once deployment complete tried

heroku open 

i end getting 404. app though runs fine on local environment.

heroku not provide standard welcome page rails 4. if did not create 1 404 page. problem should not arise if root set.

you can test creating home controller index action, create index. html.erb page , define root to: 'home#index'. heroku knows page and not receive 404 error.

getting started heroku guide: https://devcenter.heroku.com/articles/getting-started-with-rails4