Fixed crash if a .gemspec has a string for require_paths variable.
Fixed text from require_path to require_paths.  Ensured Array() on require_paths.
From attr_writer :require_paths to defined with require_paths= which sets with Array.  Using raw_require_paths as @zzak did.
In .to_ruby changed @require_paths to raw_require_paths
Merge branch 'master' of https://github.com/danielpclark/rubygems
Updated attr_writer :require_paths to def require_paths= which sets @require_paths with an Array