add test for jdk11 and updated mvn version

.gitlab-ci.yml

@@ -6,25 +6,19 @@ stages:
   - leaks
   - test
 
-##mvn:jdk7:
-##  image: maven:3.5.3-jdk-7
-##  script:
-##    - mvn clean verify -Dgpg.skip
-##    - mvn exec:java -Dexec.mainClass="be.cylab.java.wowa.training.Example" -Dexec.args="100 60 10 RWS 110"
-
 include:
   - '.gitleaks.yml'
 
 test:mvn:jdk8:
   stage: test
-  image: maven:3.5.3-jdk-8
+  image: maven:3.6.3-jdk-8
   script:
     - mvn clean verify -Dgpg.skip -Dmaven.repo.local=.m2
 
 
-##mvn:jdk11:
-##  image: maven:3.5.3-jdk-11
-##  script:
-##    - mvn clean verify -Dgpg.skip
-##    - mvn exec:java -Dexec.mainClass="be.cylab.java.wowa.training.Example" -Dexec.args="100 60 10 RWS 110"
+test:mvn:jdk11:
+  stage: test
+  image: maven:3.6.3-jdk-11
+  script:
+    - mvn clean verify -Dgpg.skip -Dmaven.repo.local=.m2