[xmlunit/xmlunit] c1928d: fix Xml -> XML

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

  Branch: refs/heads/master
  Home:   https://github.com/xmlunit/xmlunit
  Commit: c1928d668954ece07f1a87cbdd81a31f6b756f5d
      https://github.com/xmlunit/xmlunit/commit/c1928d668954ece07f1a87cbdd81a31f6b756f5d
  Author: Stefan Bodewig <ste...@fr...>
  Date:   2019-04-07 (Sun, 07 Apr 2019)

  Changed paths:
    M CONTRIBUTING.md

  Log Message:
  -----------
  fix Xml -> XML