"Deploy to Heroku" button breaks because of unsupported ruby version

[mshenfield]

When I clicked the "Deploy to Heroku" and filled out the required information, I got the following console output at the "Build App" step.

-----> Ruby app detected
-----> Compiling Ruby
       Command: 'set -o pipefail; curl -L --fail --retry 5 --retry-delay 1 --connect-timeout 3 --max-time 30 https://s3-external-1.amazonaws.com/heroku-buildpack-ruby/heroku-16/ruby-2.1.2.tgz -s -o - | tar zxf - ' failed on attempt 1 of 3.
       Command: 'set -o pipefail; curl -L --fail --retry 5 --retry-delay 1 --connect-timeout 3 --max-time 30 https://s3-external-1.amazonaws.com/heroku-buildpack-ruby/heroku-16/ruby-2.1.2.tgz -s -o - | tar zxf - ' failed on attempt 2 of 3.
 !
 !     An error occurred while installing ruby-2.1.2
 !     
 !     Heroku recommends you use the latest supported Ruby version listed here:
 !     https://devcenter.heroku.com/articles/ruby-support#supported-runtimes
 !     
 !     For more information on syntax for declaring a Ruby version see:
 !     https://devcenter.heroku.com/articles/ruby-versions
 !     
 !     
 !     Debug InformationCommand: 'set -o pipefail; curl -L --fail --retry 5 --retry-delay 1 --connect-timeout 3 --max-time 30 https://s3-external-1.amazonaws.com/heroku-buildpack-ruby/heroku-16/ruby-2.1.2.tgz -s -o - | tar zxf - ' failed unexpectedly:
 !     
 !     gzip: stdin: unexpected end of file
 !     tar: Child returned status 1
 !     tar: Error is not recoverable: exiting now
 !
 !     Push rejected, failed to compile Ruby app.
 !     Push failed

For some reason the buildpack for Ruby 2.1.2 is not able to be downloaded correctly. It looks the ruby version is not in the list of ruby versions supported by Heroku, which may be the source of the issue. To update the ruby version, it needs to be bumped in the

• the Gemfile
• .travis.yaml

Additional changes may be required to update the project to a supported ruby version.