Require Mavne 3.6.3

This addresses a warning due to plugins that require a newer version:

[ERROR] Project requires an incorrect minimum version of Maven.
[ERROR] Update the pom.xml to contain maven-enforcer-plugin to
[ERROR] force the Maven version which is needed to build this project.
[ERROR] See https://maven.apache.org/enforcer/enforcer-rules/requireMavenVersion.html
[ERROR] Using the minimum version of Maven: 3.2.5

pom.xml

@@ -85,7 +85,7 @@
             <configuration>
               <rules>
                 <requireMavenVersion>
-                  <version>3.2.5</version>
+                  <version>3.6.3</version>
                 </requireMavenVersion>
               </rules>
             </configuration>