[Checkins] [zopefoundation/persistent] 29412e: Extra slicing tests, and fix a __delslice__ issue ...

[Jason Madden]

  Branch: refs/heads/issue112
  Home:   https://github.com/zopefoundation/persistent
  Commit: 29412e6cfd2a1079b90149de72facbc600b72947
      https://github.com/zopefoundation/persistent/commit/29412e6cfd2a1079b90149de72facbc600b72947
  Author: Jason Madden <jamadden at gmail.com>
  Date:   2020-02-17 (Mon, 17 Feb 2020)

  Changed paths:
    M persistent/list.py
    M persistent/tests/test_list.py

  Log Message:
  -----------
  Extra slicing tests, and fix a __delslice__ issue on Python 2.

Found by @tseaver in https://github.com/zopefoundation/persistent/pull/115#discussion_r379928442