rubysl-json was yanked by @brixen; use json instead
Revert "Drop support for ruby 1.8"

This reverts commit a8ccb5fe08b4314bd7901bde92f5fb320028f3b4.
Revert "Prevent installing rainbow on ruby <1.9.2"

This reverts commit 6f1b242edb7c292c2161c048b5a05131bfc868e6.
Merge pull request #18 from sferik/ruby_1.8

Restore Ruby 1.8.7 compatibility