use newer junit on gemify IT to avoid jdk version issues

Author: mkristian

gem-maven-plugin/src/it/gemify-pom/pom.xml

@@ -9,8 +9,8 @@
   <url>http://maven.apache.org</url>
   <dependencies>
     <dependency>
-    <groupId>org.junit.jupiter</groupId>
-    <artifactId>junit-jupiter</artifactId>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter</artifactId>
       <version>5.10.0</version>
       <scope>test</scope>
     </dependency>
@@ -22,6 +22,10 @@
         <artifactId>gem-maven-plugin</artifactId>
         <version>@project.version@</version>
       </plugin>
+      <plugin>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>3.8.1</version>
+      </plugin>
     </plugins>
   </build>
 </project>