title: Use Scrapyd with arguments
body: <p>I'm using Scrapyd to use scrapy as webservice.</p>
  
  <p>I would like to use the curl command with parameters like this :</p>
  
  <pre><code>curl http://myip:6800/schedule.json -d project=default -d spider=myspider -d domain=www.google.fr
  </code></pre>
  
  <p>But I don't know how to get the parameter domain in the Crawler.</p>
  
  <pre><code>import scrapy
  from scrapy.spiders import CrawlSpider, Rule
  from scrapy.linkextractors import LinkExtractor
  
  class MyItem(Item):
      url = Field()
  
  class HttpbinSpider(CrawlSpider):
  
      name = "expired"
      start_urls = [domain]
  </code></pre>
  
  <p>I need to pass sometimes <strong>one domain or multiples</strong> in arguments.</p>
  
  <p>Thank's !</p>