title: handle all exception in scrapy with sentry
body: <p>I'm working on a project with scrapy for a while now, and i wanted to integrate sentry,</p>
  
  <p>I've used  <a href="https://github.com/llonchj/scrapy-sentry" rel="noreferrer">scrapy-sentry</a> but it it didn't work at all</p>
  
  <p>i tried also to implement it using Extensions but it works only if an error occurred in the spider's callback (not pipelines.py, items.py)...</p>
  
  <pre><code>from scrapy import signals
  
  from raven import Client
  
  
  class FailLogger(object):
      client = Client(settings.get('SENTRY_DSN'))
  
      @classmethod
      def from_crawler(cls, crawler):
          ext = cls()
  
          crawler.signals.connect(ext.spider_error, signal=signals.spider_error)
          return ext
  
      def spider_error(self, failure, response, spider):
          try:
              failure.raiseException()
          except:
              self.client.get_ident(self.client.captureException())
  </code></pre>
  
  <p>is there any that i can log errors (in spiders, items, pipelines ...) to sentry, like in Django?</p>
  
  <p>Thank you.</p>