[Checkins] [zopefoundation/Products.OFSP] 771f48: Try to fix TravisCI

[Michael Howitz]

  Branch: refs/heads/icemac-patch-1
  Home:   https://github.com/zopefoundation/Products.OFSP
  Commit: 771f4820e3035f1f060c3fe24f37126abaeee249
      https://github.com/zopefoundation/Products.OFSP/commit/771f4820e3035f1f060c3fe24f37126abaeee249
  Author: Michael Howitz <mac at gmx.net>
  Date:   2019-06-28 (Fri, 28 Jun 2019)

  Changed paths:
    M .travis.yml

  Log Message:
  -----------
  Try to fix TravisCI

Using xenial helped for the DateTime package.