I've been able to set up `Active Storage` file uploads and now I'm trying to return associated images when I do, for instance, `Speaker.all` or `Speaker.find(2)`.

Calling the associated endpoint I get something like:

```
{
    "id": 2,
    "name": "Rafael",
    "email": "rafael.almeida@mail-provider.com",
    "company": "XING",
    "social_media": "{\"twitter\": \"@rafaelcpalmeida\"}",
    "created_at": "2018-10-01T17:21:50.993Z",
    "updated_at": "2018-10-01T17:21:51.144Z"
}

```

How can I also return its associated avatar?