Latest heroku-buildpack-ruby from upstream

[willthames]

trafficstars

Merge in v134 of https://github.com/heroku/heroku-buildpack-ruby

To see differences:

git remote add upup https://github.com/heroku/heroku-buildpack-ruby
git fetch upup master
git diff upup/master

[tml]

:+1:

Currently, this buildpack cannot be used on Cedar-14; given that Cedar is scheduled for EOL very soon, I hope @jgarber can merge this and get the buildpack working on the new platform.