Add dry-run stage

This commit adds a `--dry-run` every time something new is commited.

This should prevent issues with the actual execution by allowing CI
testing.

.gitlab-ci.yml

@@ -2,9 +2,17 @@ image: docker.io/renovate/renovate:19
 
 stages:
   - CI
+  - Run
+
+dry-run:
+  stage: CI
+  before_script:
+    - cp config.js /usr/src/app/config.js
+  script:
+    - node /usr/src/app/dist/renovate.js --dry-run
 
 run:
-  stage: CI
+  stage: Run
   before_script:
     - cp config.js /usr/src/app/config.js
   script: