use add-opens in surefire only when running in jdk9+

Author: diegomarquezp

pom.xml

@@ -220,15 +220,6 @@
             </execution>
           </executions>
         </plugin>
-        <plugin>
-          <groupId>org.apache.maven.plugins</groupId>
-          <artifactId>maven-surefire-plugin</artifactId>
-          <configuration>
-            <!-- This arg line allows inter-module access when Gson serializes
-            the private variables of java.time.Duration -->
-            <argLine>--add-opens java.base/java.time=ALL-UNNAMED</argLine>
-          </configuration>
-        </plugin>
       </plugins>
     </pluginManagement>
   </build>
@@ -308,4 +299,25 @@
       </plugin>
     </plugins>
   </reporting>
+  <profiles>
+    <profile>
+      <id>java9</id>
+      <activation>
+        <jdk>[9,)</jdk>
+      </activation>
+      <build>
+        <plugins>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-surefire-plugin</artifactId>
+            <configuration>
+              <!-- This arg line allows inter-module access when Gson serializes
+              the private variables of java.time.Duration -->
+              <argLine>--add-opens java.base/java.time=ALL-UNNAMED</argLine>
+            </configuration>
+          </plugin>
+        </plugins>
+      </build>
+    </profile>
+  </profiles>
 </project>