Update .gitlab-ci.yml

image: ruby:2.3

variables:

  JEKYLL_ENV: production

  LC_ALL: C.UTF-8

before_script:

  - bundle install

test:

  stage: test

  script:

  - bundle exec jekyll build -d test

  artifacts:

    paths:

    - test

  except:

  - master

pages:

  stage: deploy

  script:

  - bundle exec jekyll build -d public

  artifacts:

    paths:

    - public

  only:

  - master

# The Docker image that will be used to build your app

image: node:lts