[Kotlin] Invalid enum var names

Description

When enums name start with a number, the generated code won't compile

Swagger-codegen version

2.4.0-SNAPSHOT

Swagger declaration file content or url

"enum":[
    "1name"
]

Command line used for generation

java -jar swagger-codegen-cli.jar generate -i swagger.json -c config.json -l kotlin -o tmp

Steps to reproduce

Add an enum parameter to swagger file; generate and compile.

Related issues/PRs

Suggest a fix/enhancement

The enumeration name can be prefixed by an underscore, it's done like this for the model name.

Another solution is to surround illegals names with backticks, but enum may be tricky to use (Status.1available). And what I understand of kotlin coding convention is backticks are acceptable only for names in tests.

Start by reproducing the issue with swagger-codegen-cli.jar, the supplied swagger.json enum value, and the Kotlin generator. Inspect the Kotlin generation templates or entry points responsible for enum names. Done means the generated Kotlin code compiles when an enum value begins with a number, while preserving valid names for other values.