Fix LPXC deadlock issue 

ryandotsmith/lpxc#7
remove rake tasks that use vulcan

the buildpack uses [hammer](http://github.com/hone/hammer)
Merge pull request #192 from heroku/schneems/fix-lpxc

Fix LPXC deadlock issue
Merge pull request #193 from heroku/remove_vulcan

remove rake tasks that use vulcan
Bundler 1.4.0.pre.1, set parallel install to 2
git fixes sin Bundler 1.4.0.pre.2
need to invalidate the CloudFront cache first, default to S3 for now
instrument bundler to stdout
try -j4
fix sqlite3 error detection for bundler 1.4.0
set the buildpack version to branch name
bundler 1.4.0.rc.1
update to 1.5.1
Changelog
Merge pull request #195 from heroku/bundler14

Bundler 1.5.1
More changelog
extract the BUILDPACK_VERSION into it's own file
setup path so requires work when just requiring language_pack
rake task to increment BUILDPACK_VERSION number
use ruby-git