…ome dependencies required specific ruby engines. Also changed a RUBY_VERSION reference to RUBY_ENGINE which was left over from the previous commit
… not jruby)
…back in the future
… :test grouping
--- This patch: 1. Removes the ActiveSupport::JSON engine so that Rails 3.1 can avoid a circular dependency when the Sprockets and ExecJS libraries require MultiJSON. (As the original author of ActiveSupport::JSON, Ill also be pushing for Rails to remove it and defer to MultiJSON instead.) 2. Bundles the [OkJson](https://github.com/kr/okjson) library and adds an Okjson engine that will be used if no other engines are available.
Don't fail to load the Rakefile if rspec is not present, instead print an error message and skip further along.