updated gitlab-ci file to avoid build warnings errors

    # Build React app

    - cd react-frontend/my-react-app

    - npm install

    - npm run build

    # - npm run build

    - CI=false npm run build

    # Copy React build to /blog

    - mkdir -p ../../public/blog

    - cp -r build/* ../../public/blog/

  artifacts:

    paths:

      - public