Parse and store metadata before emiting urls to fetch in parse operation

... to make sure metadata gets passed to the next stage along with the fetched content.

Here's a crawler config to test run the example in docs (https://memorious.readthedocs.io/en/latest/buildingcrawler.html#parse)

name: glitch_parse
description: Parse metadata test
pipeline:
  init:
    method: seed
    params:
      urls: 
        - https://uncovered-calico-random.glitch.me/
    handle:
      pass: fetch
  fetch:
    method: fetch
    handle:
      pass: parse 
  parse:
    method: parse
    params:
      store:
        mime_group: documents
      include_paths:
        - './/article'
      meta:
        creator: './/article/p[@class="author"]'
        title: './/h1'
      meta_date:
        published_at: './/article/time'
        updated_at: './/article//span[@id="updated"]'
    handle:
        fetch: fetch
        store: store
  store:
    method: inspect

alephdata / memorious

Parse and store metadata before emiting urls to fetch in parse operation #121