Added gitlab-ci definition for running testcontainer in gitlab

.gitlab-ci.yml

-# DinD service is required for Testcontainers
-services:
-  - name: docker:dind
-    # explicitly disable tls to avoid docker startup interruption
-    command: ["--tls=false"]
-
 variables:
-  # Instruct Testcontainers to use the daemon of DinD.
   DOCKER_HOST: "tcp://docker:2375"
-  # Instruct Docker not to start over TLS.
-  DOCKER_TLS_CERTDIR: ""
-  # Improve performance with overlayfs.
   DOCKER_DRIVER: overlay2
 
+services:
+  - name: docker:dind
+
 test:
-  image: maven:latest
   stage: test
-  script: mvn --quiet test
\ No newline at end of file
+  image: openjdk:11
+  script: ./mvnw test
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