Backstop JS setup for custom logins

scenario.json

{
  "scenarios": [
    {
      "label": "<>",
      "url": "<>",
      "onReadyScript": "<>",
      "credentials": "Do not mention this property if it uses default credentials, otherwise mention 'manager'/'stuff'/etc"
    }
  ]
}

site-config.json

{
    "url": "http://%{site-host}",
    "credentials": {
        "default": {
            "name": "%{user-name}",
            "pass": "%{user-password}"
        },
        "manager": {
            "name": "civihr_manager",
            "pass": "civihr_manager"
        },
        "stuff": {
            "name": "civihr_stuff",
            "pass": "civihr_stuff"
        }
    }
}