[Checkins] [zopefoundation/zc.relation] cb7f04: Use next instead of six.next

[GitHub]

  Branch: refs/heads/py3-compat
  Home:   https://github.com/zopefoundation/zc.relation
  Commit: cb7f04078f6bf69ab68062d8f373cc45816c581d
      https://github.com/zopefoundation/zc.relation/commit/cb7f04078f6bf69ab68062d8f373cc45816c581d
  Author: ale-rt <alessandro.pisa at gmail.com>
  Date:   2018-04-04 (Wed, 04 Apr 2018)

  Changed paths:
    M src/zc/relation/catalog.py
    M src/zc/relation/searchindex.py

  Log Message:
  -----------
  Use next instead of six.next