[Checkins] [zopefoundation/BTrees] 0218d3: Manually install persistent for travis.

[GitHub]

  Branch: refs/heads/macpython
  Home:   https://github.com/zopefoundation/BTrees
  Commit: 0218d3045a40c7f79487359e4830151c6ea2e524
      https://github.com/zopefoundation/BTrees/commit/0218d3045a40c7f79487359e4830151c6ea2e524
  Author: Jason Madden <jamadden at gmail.com>
  Date:   2017-01-18 (Wed, 18 Jan 2017)

  Changed paths:
    M .travis.yml

  Log Message:
  -----------
  Manually install persistent for travis.