[xmlunit/xmlunit] 09816e: prepare the 2.6.0 release

[GitHub <no...@gi...>]

  Branch: refs/tags/v2.6.0
  Home:   https://github.com/xmlunit/xmlunit
  Commit: 09816e917509cce3f04d5a7506c7b0fbac8a6a60
      https://github.com/xmlunit/xmlunit/commit/09816e917509cce3f04d5a7506c7b0fbac8a6a60
  Author: Stefan Bodewig <ste...@fr...>
  Date:   2018-04-22 (Sun, 22 Apr 2018)

  Changed paths:
    M RELEASE_NOTES.md
    M pom.xml
    M xmlunit-core/pom.xml
    M xmlunit-legacy/pom.xml
    M xmlunit-matchers/pom.xml
    M xmlunit-placeholders/pom.xml

  Log Message:
  -----------
  prepare the 2.6.0 release