Do not use cache for CI, and merge build and jar job.

.gitlab-ci.yml

 stages:
 - build
 - test
-- jar
 
 build:
   image: openjdk:8
   stage: build
   script:
-    - ./gradlew --console=plain --build-cache assemble
-  cache:
-    key: "$CI_COMMIT_REF_NAME"
-    policy: push
+    - ./gradlew --console=plain assemble jar
+  artifacts:
     paths:
-      - build
-      - .gradle
+      - "/builds/jastadd/relational-rags/build/libs/*relast*.jar"
 
 test:
   image: openjdk:8
   stage: test
   script:
-    - ./gradlew --continue --console=plain --info check
-  cache:
-    key: "$CI_COMMIT_REF_NAME"
-    policy: pull
-    paths:
-      - build
-      - .gradle
-
-jar:
-  image: openjdk:8
-  stage: jar
-  script:
-    - ./gradlew --continue --console=plain --info jar
-  cache:
-    key: "$CI_COMMIT_REF_NAME"
-    policy: pull
-    paths:
-      - build
-      - .gradle
-  artifacts:
-    paths:
-      - "/builds/jastadd/*/build/libs/*relast*.jar"
+    - ./gradlew --console=plain --info test