Unable to deser the "Basic Structure" example from the OpenAPI v2 spec

[pwoolcoc]

this crate is unable to deserialize the document shown here, in the OpenAPI v2 spec: https://swagger.io/docs/specification/2-0/basic-structure/ . It fails with the following error:

---- test_basic_structure stdout ----
thread 'test_basic_structure' panicked at 'Couldn't deser doc: Yaml(Message("data did not match any variant of untagged enum OpenApi", None))', src/lib.rs:34:15
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Here is the code I used to generate the error:

#[test]
fn test_basic_structure() {
    use std::io::{self, Cursor};

    let doc = r#"swagger: "2.0"
info:
  title: Sample API
  description: API description in Markdown.
  version: 1.0.0

host: api.example.com
basePath: /v1
schemes:
  - https

paths:
  /users:
    get:
      summary: Some text
      description: Some more text
      produces:
        - application/json
      responses:
        200:
          description: OK"#.to_string();

    let bytes = doc.as_bytes().to_vec();
    let mut bytes = Cursor::new(bytes);

    let api = openapi::from_reader(&mut bytes).expect("Couldn't deser doc");
}

[pwoolcoc]

I think this is related to this serde_yaml issue, if so I will close this: dtolnay/serde-yaml#165