Specify maven plugin versions to avoid inconsistent jars

Author: TheBlueMatt

pom.xml

@@ -73,6 +73,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-source-plugin</artifactId>
+                <version>3.2.0</version>
                 <executions>
                     <execution>
                         <id>attach-sources</id>
@@ -85,6 +86,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-javadoc-plugin</artifactId>
+                <version>3.3.1</version>
                 <configuration>
                     <skip>${org.lightningdevkit.skipdocs}</skip>
                 </configuration>