$ heroku login $ heroku create app-test --buildpack https://github.com/heroku/heroku-buildpack-multi.git
$ vi .buildpacks
https://github.com/virtualstaticvoid/heroku-buildpack-r.git https://github.com/heroku/heroku-buildpack-ruby.git
Then you can launch R on Heroku server.
$ heroku run R
S.Yatsuzuka