[xmlunit/xmlunit] 03d8e2: run compatibility tests in a subshell

[Stefan B. <no...@gi...>]

  Branch: refs/heads/master
  Home:   https://github.com/xmlunit/xmlunit
  Commit: 03d8e2f02f4f32697a4eeddfec54dcb6ac693dff
      https://github.com/xmlunit/xmlunit/commit/03d8e2f02f4f32697a4eeddfec54dcb6ac693dff
  Author: Stefan Bodewig <ste...@fr...>
  Date:   2020-05-04 (Mon, 04 May 2020)

  Changed paths:
    M .travis.yml

  Log Message:
  -----------
  run compatibility tests in a subshell