Renegerated gemspec -- please re-release 1.1.1

@lgs the gemspec that was released for v 1.1.1 is missing a required file (real_time_group_by.rb), and as result the official gem breaks when you try to use it with Rails.

I rebuilt the gemspec with `rake gemspec:generate`. Please deploy this (overwrite the existing 1.1.1 if possible since the existing deploy is broken.)