{
  "assetPath": "/spotlight/",
  "port": 3057,
  "backdropUrl": "http://spotlight.perfplat.dev/backdrop-stub/{{ data-group }}/{{ data-type }}",
  "screenshotTargetUrl": "http://spotlight.perfplat.dev",
  "screenshotServiceUrl": "http://spotlight.perfplat.dev:3000",
  "govukHost": "spotlight.dev.gov.uk"
}

{
  "assetPath": "/spotlight/",
  "port": 3057,
  "backdropUrl": "https://www.preview.performance.service.gov.uk/data/{{ data-group }}/{{ data-type }}",
  "screenshotTargetUrl": "http://localhost:3057",
  "screenshotServiceUrl": "http://localhost:3060",
  "govukHost": "www.preview.alphagov.co.uk"
}

Switch dev config to point to preview
Switch dev config to point to preview

Most development is happening outside of the dev vm so we should point
to preview rather than expecting services to be running locally.
