Add Support for OAS v3.1

[stuft2]

Putting this upcoming change on our radar. Supporting version 3.1.0 gives us the ability to use the full JSON schema specification in the Schema Object.

OAI/OpenAPI-Specification#2370

[stuft2]

Version 3.1 of the OpenAPI Specification was released: OAI/OpenAPI-Specification#2462

[mrehanabbasi]

I will really like this as currently there is no complete validator for OAS 3.1.

[Gi60s]

Version 2 of this tool will be supporting OAS 3.1. I'm not sure on the release date yet, but it is mostly done. We're working on fully testing it still.

[mrehanabbasi]

Looking forward to a speedy release.

[BryanCrotazGivEnergy]

Added a PR for some of the OAS 3.1 fields in #165