upgrade to bundler 1.3.2
bump to v54
update changelog
Revert "upgrade to bundler 1.3.2"

This reverts commit 4091c08b58eecbbdff0288c8723522e9b08c541d.
bump to v55
update changelog
Revert "Revert "upgrade to bundler 1.3.2""

This reverts commit 3fc9718e47cff36e30acc4c305994cff75c19f14.
require psyched_yaml in the syck hack
ruby 1.8.7 doesn't autoload rubygems
bump to v56
update changelog
Update link to vulcan gem
Merge pull request #73 from sumbach/patch-1

Update link to vulcan gem in README
write bundler version
Fix bundler git gemspec bug.

Bundler 1.3.0.pre.8 broke backwards compatibility with gemspecs.
6548e31e8ad061403d65505d7d2e17c489b262cc changes how gemspecs are being
generated which is causing problems with git gemspecs that are not self
contained. See https://gist.github.com/hone/5043f02bea633fd1a844 for the
differences in the gemspec.
v57 bump
only clear the cache if the bundle contains git gems
scope bundle cache removal to git gems
update changelog
fix bundle install for ruby 1.8.7

Bundler gets removed from the `$LOAD_PATH` for some reason in ruby 1.8.7.
This means we shouldn't try to require something from bundler here.

> Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native
> extension.
>
>        /home/hone/.rvm/rubies/ruby-1.8.7-p371/bin/ruby extconf.rb
> /home/hone/.rvm/rubies/ruby-1.8.7-p371/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:36:in
> `gem_original_require': no such file to load -- bundler/psyched_yaml
> (LoadError)
>         from
> /home/hone/.rvm/rubies/ruby-1.8.7-p371/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:36:in
> `require'
>         from
> /home/hone/Projects/heroku_work/heroku-buildpack-ruby/vendor/syck_hack.rb:15