Code snippet from post about CircleCI with React - sequential workflow

config.yml

version: 2
jobs:
  build:
    docker:
      - image: circleci/node:8.2.1
    steps:
      - checkout
      - run: echo "My first job is build."
  test:
    steps:
      - checkout
      - run: echo "My second job is test."
workflows:
  version: 2
  build_and_test:
    jobs:
      - test
      - build:
        requires: 
          - test