def versions(name)
        if @data.key?(name)
          return @data[name]
        end

        u = URI.parse "http://rubygems.org/api/v1/dependencies?gems=#{name}"
        str = Net::HTTP.get(u)

        Marshal.load(str).each do |ver|
          @data[ver[:name]] << ver
        end

        @data[name]
      end
Return data for all versions of the gem +name+.