Fix superclass mismatch for class StringIO
Fix superclass mismatch for class StringIO

    % ruby -I lib -r ffi_yajl/ffi -r stringio -e ''
    /usr/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require': superclass mismatch for class StringIO (TypeError)
            from /usr/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require'

chef/ffi-yajl,h4ck3rm1k3/ffi-yajl,kou/ffi-yajl,h4ck3rm1k3/ffi-yajl,chef/ffi-yajl,h4ck3rm1k3/ffi-yajl,kou/ffi-yajl,chef/ffi-yajl,kou/ffi-yajl