Update java version for gitlab actions

Author: LukasLechnerDev

.github/workflows/build_and_test.yml

@@ -13,7 +13,7 @@ jobs:
       - name: Set Up JDK
         uses: actions/setup-java@v1
         with:
-          java-version: 1.8
+          java-version: 1.11
 
       - name: Run Tests
         run: ./gradlew test