Made the pipeline run only if Dockerfile changed

.gitlab-ci.yml

@@ -13,3 +13,6 @@ docker:
     - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
     - docker build -t $CI_REGISTRY_IMAGE:latest .
     - docker push $CI_REGISTRY_IMAGE:latest
+  rules:
+    - changes:
+        - Dockerfile