[R] Enhancements to R generator

[wing328]

Description

Here are a list of enhancements to R generator:

• add auto-generated README.md
• add auto-generated API, model documentation
• better authentication support using {{#authMethods}} ... {{/authMethods}}
• setup CI to cover R Petstore client

Swagger-codegen version

Latest master

Suggest a fix/enhancement

If anyone has other suggestions or wants work on any of these enhancements, please reply to let us know.

[sneumann]

Hi, I am interested to use / test the R generator, but am lacking any pointers how to use it.
What would be the right place to get / put examples and concepts ?

[wing328]

@sneumann thanks for offering help. The auto-generated R petstore sample would be a good starting point.