def update(response, url)
      @log.puts "Scanning: #{url}"
      if response.kind_of?(Net::HTTPClientError) or response.kind_of?(Net::HTTPServerError)
        @log.puts "#{response.code} encountered for #{url}"
      end
    end
def update(response, url)
      @log.puts "Scanning: #{url}"
      if response.kind_of?(Net::HTTPClientError) or response.kind_of?(Net::HTTPServerError)
        @log.puts "#{response.code} encountered for #{url}"
      end
    end
Creates a new Observer object
 Called by the Observable module through Webcrawler.