adding jar plugin

Signed-off-by: Tihomir Surdilovic <tihomir@temporal.io>

Author: tsurdilo

pom.xml

@@ -79,6 +79,7 @@
         <version.plantuml>8059</version.plantuml>
         <version.graphviz>0.17.0</version.graphviz>
         <version.fmt-maven-plugin>2.9</version.fmt-maven-plugin>
+        <version.jar.plugin>3.2.0</version.jar.plugin>
         <!-- Checkstyle props -->
         <checkstyle.failOnViolation>true</checkstyle.failOnViolation>
         <checkstyle.header.template><![CDATA[
@@ -290,6 +291,18 @@
                 <artifactId>fmt-maven-plugin</artifactId>
                 <version>${version.fmt-maven-plugin}</version>
             </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-jar-plugin</artifactId>
+                <version>${version.jar.plugin}</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>test-jar</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-source-plugin</artifactId>