Build the docker image using the cache

.gitlab-ci.yml

@@ -17,7 +17,8 @@ build:
    stage: build
    script:
       - echo building $IMAGE and releasing as $RELEASE_IMAGE
-      - docker build -t $IMAGE .
+      - docker pull $RELEASE_IMAGE || true
+      - docker build --pull -t $IMAGE --cache-from $RELEASE_IMAGE  .
       - docker push $IMAGE
       - docker tag $IMAGE $RELEASE_IMAGE
       - docker push $RELEASE_IMAGE