Explictly sets the prefix when building node
Cache fetched bundler and parsed bundle.
init
Realize the bundle if bundler_path is called before bundle.
Really just one instance of things.
Less magic.
Merge branch 'master' into cache-parsed-bundle
Create database_yml again to make it work with rails 4.0.0.rc.  Refer to: https://github.com/rails/rails/commit/dd5a80dc3da794f9296ec199c492a398589257a0.
Show full backtrace on exceptions

From conversation https://github.com/grosser/parallel_tests/issues/221
extract cache into its own class
document when cache_dir is nil
extract metadata into its own class
fix sqlite3 error detection for newer bundler
store buildpack ruby_version data
install Ruby 1.9.3 by default
install last version of ruby used
don't require cache for using metadata
update comment
set ruby_version_env_var properly
fix new_app? detection code