environments:
  - staging
  - production
  - test

optional_variables:
  - MyOptVar1
  - MyOptVar2
required_variables:
  - MyReqVar1
  - MyReqVar2

slack_webhook_url: https://hooks.slack.com/services/.../.../...

staging:
  optional_variables:
    - Staging_MyOptVar1
    - Staging_MyOptVar2
  required_variables:
    - Staging_MyReqVar1
    - Staging_MyReqVar2

  slack_webhook_url: https://hooks.slack.com/services/.../.../...

production:
  optional_variables:
    - Production_MyOptVar1
    - Production_MyOptVar2
  required_variables:
    - Production_MyReqVar1
    - Production_MyReqVar2

  slack_webhook_url: https://hooks.slack.com/services/.../.../...