Set buildpack cache dir in config
Bump ruby buildpack

ruby buildpack 7c62bc4..90d4896
April Yu & Mark Rushakoff (2):
      Merge remote-tracking branch 'heroku/master'
      Fix failing spec after merge

Maria Shaldibina and Nate Clark (5):
      use environment variable for buildpack cache directory
      Merge remote-tracking branch 'heroku/master'
      Update bundler to 1.3.2
      Merge branch 'master' of github.com:cloudfoundry/heroku-buildpack-ruby
      Remove output from package fetcher

Richard Schneeman (1):
      Merge pull request #73 from sumbach/patch-1

Sam Umbach (1):
      Update link to vulcan gem

Terence Lee (11):
      upgrade to bundler 1.3.2
      bump to v54
      update changelog
      Revert "upgrade to bundler 1.3.2"
      bump to v55
      update changelog
      Revert "Revert "upgrade to bundler 1.3.2""
      require psyched_yaml in the syck hack
      ruby 1.8.7 doesn't autoload rubygems
      bump to v56
      update changelog