jm/toml — pull request #28 by rjocoleman (2014-02-16 23:49:24+00:00)
Title: convert nil to empty string

Currently if a key's value is `nil` when using `TOML::Generator.new(hash).body` a undefined method error is thrown: `NoMethodError: undefined method 'to_toml' for nil:NilClass`

This PR converts supports `nil.to_toml` by converting it into an empty string.