progrium/buildstep — pull request #56 by icco (2013-10-30 01:24:00+00:00)
Title: pass bin/release $build_root instead of $app_root

This is needed by heroku-buildpack-ruby because of the following line in bin/release:

```ruby
release = Pathname.new(ARGV.first).join("tmp/heroku-buildpack-release-step.yml")
```

That file does not exist in `$app_root` or `$cache_root`.