Store artifacts and only need the submodule during build

.gitlab-ci.yml

@@ -1,13 +1,15 @@
 image: golang:1.9
 
-before_script:
-  - git submodule sync --recursive
-  - git submodule update --init --recursive
-
 gohugo-build:
   script:
+    - git submodule sync --recursive
+    - git submodule update --init --recursive
     - go get github.com/gohugoio/hugo
     - hugo
+  artifacts:
+    expire_in: 1 week
+    paths:
+      - public
 
 gohugo-deploy:
   image: kyleondy/alpine-rsync