Psych is a YAML parser and emitter. Psych leverages libyaml[http://pyyaml.org/wiki/LibYAML] for its YAML parsing and emitting capabilities. In addition to wrapping libyaml, Psych also knows how to serialize and de-serialize most Ruby objects to and from the YAML format.
Gemfile gem 'psych', '~> 2.0.4'
install gem install psych -v 2.0.4