[cpprest] Dots and dashes are allowed in C++ identifiers.

[Jauler]

Description

When generating cpprest dots and dashes are allowed for C++ identifier names which causes uncompilable code like:

class  Io.k8s.kubernetes.pkg.api.v1.Service
    : public ModelBase
{
...

Swagger-codegen version

2.4.0-SNAPSHOT from docker hub: https://hub.docker.com/r/swaggerapi/swagger-codegen-cli/

Swagger declaration file content or url

https://raw.githubusercontent.com/kubernetes/kubernetes/v1.10.4/api/openapi-spec/swagger.json

Command line used for generation

docker run swaggerapi/swagger-codegen-cli generate  --lang cpprest --output /output -i https://raw.githubusercontent.com/kubernetes/kubernetes/v1.10.4/api/openapi-spec/swagger.json

Steps to reproduce

run:

docker run swaggerapi/swagger-codegen-cli generate  --lang cpprest --output /output -i https://raw.githubusercontent.com/kubernetes/kubernetes/v1.10.4/api/openapi-spec/swagger.json

After generating any class in model directory will have such invalid names.

Suggest a fix/enhancement

Maybe map dots to "_", but care must be taken to avoid name clashes.