Generator 'gem' action doesn't escape version properly.

I've written a patch for the behavior that the 'gem' action in
generators doesn't properly escape the version string, thus causing it
to error out if you try to apply a gem action and subsequently do much
of anything. Patch is here:

https://rails.lighthouseapp.com/projects/8994/tickets/3901-patch-generator-gem-command-doesnt-accept-versions

Thanks,
Michael Bleigh