Update .gitlab-ci.yml

.gitlab-ci.yml

@@ -14,4 +14,12 @@ image_build:
   script: |
     CI_COMMIT_SHA_7=$(echo $CI_COMMIT_SHA | cut -c1-7)
     docker build --tag $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA_7 .
-    docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA_7
\ No newline at end of file
+    docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA_7
+  only:
+    refs:
+      - branches
+    changes:
+      - Dockerfile
+      - requirements.txt
+      - install.R
+      - environment.yml
\ No newline at end of file