I'd like to avoid things like #4251 in the future, let's see how people think about it. We'll decide which style to use before releasing 1.14 based on the 👍/👎 and change the style if one's vote (👍s - 👎s) is greater than another one about 30%, otherwise stay as-is (i.e., do indent).

a:
  - b
  - c

before_script:
  - command
  - command
  - command
stages:
  - test
  - test
  - test
other:
  - other
  - other
  - other

a:
- b
- c

before_script:
- command
- command
- command
stages:
- test
- test
- test
other:
- other
- other
- other