XMLUnit for Java 2.6.2 Released

This release mainly fixes interop problems with more recent AssertJ versions and the Java module system.

The full list of changes:

• xmlunit-assertj can now be used with AssertJ 3.9.1+ as well as 2.9.x.
  Issue #135.

• added a new TypeMatcher to the xmlunit-matchers module that can be
  used to conveniently translate XPath result strings into numbers or
  booleans and verify they match type safe assertions.
  Issue #133 via PR
  #137.

• fixed the Automatic-Module-Name of all modules to be valid Java
  identifiers.
  Issue #136.