test checking compilation compatibility with java 11

.gitlab-ci.yml

@@ -209,6 +209,17 @@ build_war:
     - ant maven-build
     - cp web/target/web-1.0.war minerva.war
 
+java_11_compatibility:
+  image: maven:3.6-jdk-11
+  stage: test
+  script:
+    - apt-get update
+    - apt-get install -y curl gnupg git ant
+    - curl -sL https://deb.nodesource.com/setup_9.x | bash -
+    - apt-get install -y nodejs
+
+    - mvn clean install -DskipTests=true
+
 dependency_conflict_check:
   image: maven:3.6.0-jdk-8
   stage: test