Capitalize the objects in scala

## Background and questions

Now in official swagger-java generator, the objects in `#/definitions` will be capitalized when generating, but in `guardrail`, this feature is missing.

## Example

Say I have a object like:

```
"healthStatus": {
"type": "object",
"properties": {
"status": {
"description": "Status always contains \"ok\".",
"type": "string",
}
}
}
```

`guardrail` will generate the code like:

```
case class healthStatus(status: Option[String] = None)
```

But what I want is `HealthStatus`