s3 custom data example

custom-data.json

{
  "s3": {
    "some-file.txt": {
      "href": "https://s3.amazonaws.com/<bucket>/<userid>/some-file.txt",
      "lastModified": "2016-09-19T17:59:22.364Z"
    },
    "another-file.txt": {
      "href": "https://s3.amazonaws.com/<bucket>/<userid>/another-file.txt",
      "lastModified": "2016-09-19T17:59:22.364Z"
  }
}