Add build via Gitlab CI

.gitlab-ci.yml

@@ -0,0 +1,17 @@
+image: ruby:2.5-alpine
+
+variables:
+  JEKYLL_ENV: production
+  LC_ALL: en_US.UTF-8
+
+before_script:
+  - bundle install --path=vendor/
+
+build site:
+  stage: build
+  script:
+  - bundle exec jekyll build -d public
+  artifacts:
+    expire_in: 1 month
+    paths:
+    - public