incorrect processing of the enum datastructure

Here is my sample API blueprint

_test-enum-datastructure.apib_

```
FORMAT: 1A

HOST: http://localhost:3000

# CustomerData API

test enum API

# Data Structures

## clients (enum)
+ Members
+ A
+ B
+ C
+ D

# Customers [/v1/test]

## Create customer [POST /v1/test]

+ Request (application/json)
+ Attributes (object)
+ uuid: wWinmNPfwuly (string)
+ client: A (clients)

+ Response 200 (application/json)
+ Attributes (boolean)
+ Sample: false
```

Which results to:

As you see in schema part, it doesn't understand that client is enum. However, I consider it's described in the correct format.

This particular format would change the situation:

```
## clients (enum)
+ A
+ B
+ C
+ D
```

But, it doesn't looks correct and some tools (I have tested with drakov https://github.com/Aconex/drakov) are failing with that format.

Any thoughts? I think the first one is correct.

Start by reproducing the issue with the provided test-enum-datastructure.apib sample and inspect the generated schema shown in the report. Trace how the clients enum data structure and the client attribute are processed; done means the schema recognizes client as an enum while preserving the documented API Blueprint format.

Written by the indexing model from the issue text.