Vendor the external cookbooks

Knife-Zero doesn't include Berkshelf support, so vendoring everything in
the repo is convenient again

cookbooks/chef-sugar/CONTRIBUTING.md

@@ -0,0 +1,20 @@
+Contributing to Chef Sugar
+===============================
+The process for contributing to Chef sugar is rather straight-forward. It is unlikely that you'll need to modify the actual Chef recipe, so it's assumed that you want to work on the Gem itself.
+
+1. Fork the repository on GitHub.
+2. Clone your fork.
+3. Create a new, semantically-named branch:
+
+        $ git checkout -b my_feature_branch
+
+4. Make any changes, ensuring you write adequate test coverage.
+5. Document your changes (YARD).
+6. Run the tests (make sure they pass).
+7. Submit a Pull Request on GitHub.
+8. (optional) Ping me on Twitter (@sethvargo)
+
+Additionally, please **DO NOT**:
+- Modify the version of the cookbook or gem.
+- Update the CHANGELOG
+- Make unnecessary changes to the gemspec