Be able to add files to the eval home. See below.
Be able to add files to the eval home. See below.

This lets you add arbitrary files into the evaluation home.
The files must be in the form of:

```
"files": {
  "filename.here": "base64-encoded file contents here"
}
```

This allows you to upload any kind of file including media
(pictures, etc). Files are deleted immediately after an evaluation takes
place.

eval-so/frontend,eval-so/frontend