Update .gitlab-ci.yml file

.gitlab-ci.yml

@@ -59,3 +59,15 @@ build-container:
     - docker build -t $TAG_COMMIT -t $TAG_LATEST .
     - docker push $TAG_COMMIT
     - docker push $TAG_LATEST
+
+update-website:
+  image: docker
+  stage: deploy
+  rules:
+    - if: $CI_COMMIT_BRANCH == "publish" && $CI_PIPELINE_SOURCE == "push"
+  script:
+    - docker-compose pull $CI_PROJECT_NAME
+    - docker-compose up -d
+  environment:
+    name: production
+    url: https://interactivetextbooks.citg.tudelft.nl/