Update README to mention support for Rails 3.2
Update README to mention support for Rails 3.2

michael-harrison/jasminerice,charliesome/better_jasminerice,carolineartz/Polity,4justinstewart/Polity,michael-harrison/jasminerice,4justinstewart/Polity,percyhanna/mocha-rice,percyhanna/mocha-rice,carolineartz/Polity