Bump xmlunit to 2.10.3

https://github.com/xmlunit/xmlunit/releases/tag/v2.10.3

JIRA: LIGHTY-368
Signed-off-by: tobias.pobocik <tobias.pobocik@pantheon.tech>
(cherry picked from commit c12fdc9)

Author: Tobianas

examples/parents/examples-bom/pom.xml

@@ -77,7 +77,7 @@
             <dependency>
                 <groupId>org.xmlunit</groupId>
                 <artifactId>xmlunit-core</artifactId>
-                <version>2.10.0</version>
+                <version>2.10.3</version>
             </dependency>
         </dependencies>
     </dependencyManagement>