Cache everything one level deeper (inside $cache_dir/node) to avoid clobbering cached artifacts from other buildpacks.
Store node-version textfile in new .heroku directory, in the slug _and_ the cache.
Merge pull request #95 from heroku/namespaced-cache

Namespaced caching and node runtime version tracking
write a default npmrc
add a status message about npmrc
Merge pull request #98 from heroku/npm-cert-bug

npm cert bug
Merge branch 'master' of https://github.com/heroku/heroku-buildpack-nodejs