do our swagger/openapi definitions support auto-generation of api clients?

I spoke to Matthew Lincoln, the author of https://github.com/mdlincoln/hypothesisr, and with a user of that wrapper who asked about whether hypothesisr might be submitted to rOpenSci. Matthew says he's not doing anything further with hypothesisr and suggests a more modern R-based Hypothesis client could be made by pointing https://github.com/bergant/rapiclient at https://h.readthedocs.io/en/latest/api-reference/hypothesis-v1.yaml.

Here's what I found in R:

```
> library(rapiclient)
>
> h_api = get_api(url= "https://h.readthedocs.io/en/latest/api-reference/hypothesis-v1.yaml")
Error in parse_con(txt, bigint_as_char) :
lexical error: invalid char in json text.
```

Output from a validator: http://online.swagger.io/validator/debug?url=https://h.readthedocs.io/en/latest/api-reference/hypothesis-v1.yaml

Do we expect this should work, and should be a way to create a Hypothesis API client for R?