Try to use environ var to cache Gems

.gitlab-ci.yml

@@ -7,10 +7,10 @@ variables:
   JEKYLL_ENV: production
   LC_ALL: C.UTF-8
   GIT_SUBMODULE_STRATEGY: recursive
+  BUNDLE_USER_HOME: ./bundle
 
 # Build is in `before_script` because it's the same for both deployments
 before_script:
-  - mv usr-local-bundle /usr/local/bundle || true   # Move extracted cache to its original place
   - apk add npm
   - npm install
   - bundle install
@@ -18,7 +18,6 @@ before_script:
   - jekyll build -d public
   - ./scripts/purgecss.sh public
   - ./scripts/minifycssjs.sh public
-  - mv /usr/local/bundle usr-local-bundle || true   # Move cache to workdir so that GitLab will pick it up
 
 deploy-prod:
   stage: deploy
@@ -32,7 +31,7 @@ deploy-prod:
   cache:
     key: build-deps
     paths:
-      - "usr-local-bundle/"
+      - "bundle/"
       - "node_modules/"
   only:
   - master
@@ -47,7 +46,7 @@ pages:
   cache:
     key: build-deps
     paths:
-      - "usr-local-bundle/"
+      - "bundle/"
       - "node_modules/"
   only:
   - develop