ruby182: remove inaccurate caveats
ruby182: remove inaccurate caveats

Ruby 1.8.2 didn't come with rubygems.

jimhe/homebrew-versions,Ashton-W/homebrew-versions,DomT4/homebrew-versions,coeligena/homebrew-verscustomized,UniqMartin/homebrew-versions,heuermh/homebrew-versions