[Checkins] [zopefoundation/zope.traversing] 84bf73: Use tox in Travis tests

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/zopefoundation/zope.traversing
  Commit: 84bf736ba0721dd6ab4b9f3b0e2cd19ce710e23b
      https://github.com/zopefoundation/zope.traversing/commit/84bf736ba0721dd6ab4b9f3b0e2cd19ce710e23b
  Author: Marius Gedminas <marius at gedmin.as>
  Date:   2014-12-22 (Mon, 22 Dec 2014)

  Changed paths:
    M .travis.yml

  Log Message:
  -----------
  Use tox in Travis tests

Because currently all builds fail with

  TypeError: isinstance() arg 2 must be a class, type, or tuple of classes and types

deep in zope.interface (e.g. https://travis-ci.org/zopefoundation/zope.traversing/jobs/44704784)