Sample no longer runs on Heroku

[jpatokal]

This sample is now so old that it no longer runs on Heroku itself:

remote:  !
remote:  !     An error occurred while installing ruby-2.2.1
remote:  !     
remote:  !     This version of Ruby is not available on Heroku-18. The minimum supported version
remote:  !     of Ruby on the Heroku-18 stack can found at:
remote:  !     
remote:  !     https://devcenter.heroku.com/articles/ruby-support#supported-runtimes

It looks like https://github.com/heroku/ruby-getting-started is the current version of this, so please deprecate and add pointers to the new one. (This still ranks highly in search results.)