This adds backward compatibility with Rack versions < 1.1. Still lots of people on Rails < 2.3.6, this enables them to use Jasmine gem.
Compatibility with Rack version ~>1.0
Chad, thanks for this. I'll have to update the test matrix on travis so we're explicitly checking compatibility with Rack 1.0 before I merge this to HEAD (since there's otherwise no tests here), but no, I don't see any reason not to add this.