Update maven-pmd-plugin from 3.5 to 3.12.0.

Author: Gary Gregory

pom.xml

@@ -295,7 +295,7 @@
       </plugin>
       <plugin>
         <artifactId>maven-pmd-plugin</artifactId>
-        <version>3.5</version>
+        <version>3.12.0</version>
         <configuration>
           <targetJdk>${maven.compiler.target}</targetJdk>
         </configuration>