Exclude the CONTRIBUTING file from the rat check
diff --git a/pom.xml b/pom.xml
index 722bdf7..4817831 100644
--- a/pom.xml
+++ b/pom.xml
@@ -110,6 +110,7 @@
             <exclude>**/README.md</exclude>
             <exclude>**/README.txt</exclude>
             <exclude>**/DEPENDENCIES</exclude>
+            <exclude>**/CONTRIBUTING.md</exclude>
 
             <!-- reference data lists -->
             <exclude>**/*json</exclude>