Try stack docker CI build

.gitlab-ci.yml

@@ -9,4 +9,11 @@ build:
   stage: build
   script:
     - docker build -t $CI_REGISTRY_IMAGE .
-    - docker push $CI_REGISTRY_IMAGE
\ No newline at end of file
+    - docker push $CI_REGISTRY_IMAGE
+
+stackdockerbuild:
+  stage: build
+  only:
+    - master
+  script:
+    - stack --docker build