[xmlunit/xmlunit] ddbf00: let's see whether OpenJDk 17 is available on Travis

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

  Branch: refs/heads/main
  Home:   https://github.com/xmlunit/xmlunit
  Commit: ddbf008934f2fd352b232267978a91ac2c038b01
      https://github.com/xmlunit/xmlunit/commit/ddbf008934f2fd352b232267978a91ac2c038b01
  Author: Stefan Bodewig <ste...@fr...>
  Date:   2021-10-03 (Sun, 03 Oct 2021)

  Changed paths:
    M .travis.yml

  Log Message:
  -----------
  let's see whether OpenJDk 17 is available on Travis