def read_file(file, prerelease = false)
      destination = Gemirro.configuration.destination
      file_dst = File.join(destination, file)
      unless File.exist?(file_dst)
        File.write(file_dst, @source.fetch_versions) unless prerelease
        File.write(file_dst, @source.fetch_prerelease_versions) if prerelease
      end

      File.read(file_dst)
    end
def read_file(file, prerelease = false)
      destination = Gemirro.configuration.destination
      file_dst = File.join(destination, file)
      unless File.exist?(file_dst)
        File.write(file_dst, @source.fetch_versions) unless prerelease
        File.write(file_dst, @source.fetch_prerelease_versions) if prerelease
      end

      File.read(file_dst)
    end
Read file if exists otherwise download its from source

 @param [String] file name
 @param [TrueClass|FalseClass] prerelease Is prerelease or not