title: Scrapy returning a empty json file
body: <p>I am trying to get data from a website, everything seems to be correct and the xpath was tested on the shell.</p>
  
  <pre><code># -*- coding: utf-8 -*-
  
  from scrapy.contrib.spiders import CrawlSpider
  
  
  class KabumspiderSpider(CrawlSpider):
      name = "kabumspider"
      allowed_domain = ["www.kabum.com.br"]
      start_urls = ["https://www.kabum.com.br"]
  
  
  def parse(self, response):
          categorias = response.xpath('//p[@class = "bot-categoria"]/a/text()').extract()
          links = response.xpath('//p[@class = "bot-categoria"]/a/@href').extract()
  
          for categoria in zip(categorias, links):
  
              info = {
                  'categoria': categoria[0],
                  'link': categoria[1],
              }
              yield info
  </code></pre>
  
  <p>Although, the output seems to be:</p>
  
  <pre><code>[
  </code></pre>
  
  <p>What is wrong with my code?</p>