Add an environment variable for tokenURL

[MartinThoma]

When I read my OpenAPI 3.0.3 yaml file, I have one oauth2 security scheme defined. This one has a tokenURL which is added as plain text to every endpoint that uses this security scheme.

This is not so nice as I have multiple environments on which I test the same API. This means I have to go through every single endpoint and make this a variable to be able to test the API properly.

It would be super nice if relative URLs worked and the base_url environment variable was used. However, relative URLs seem not to be allowed for security scheme objects

Is it maybe possible to write the OpenAPI doc in a way to make this relative, e.g. using a servers object?