[Checkins] [zopefoundation/persistent] db2757: Avoid resource warnings under Py3k.

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/zopefoundation/persistent
  Commit: db2757426c80f904a51d3bbacdd1874bdc63b032
      https://github.com/zopefoundation/persistent/commit/db2757426c80f904a51d3bbacdd1874bdc63b032
  Author: Tres Seaver <tseaver at palladion.com>
  Date:   2014-12-16 (Tue, 16 Dec 2014)

  Changed paths:
    M setup.py

  Log Message:
  -----------
  Avoid resource warnings under Py3k.

Also, work around edge case on Travis where files aren't found.