[Typescript][AngularJS] Enum creates invalid method header

Description

I've created a POST method with the following parameter and generated the typescript-angularjs client via editor.swagger.io

parameters:
        - in: query
          name: foo
          enum:
            - 'test'
            - 'hallo'
          description: image
          required: true
          type: string

The resulting method header in typescript is invalid:

public test (foo: models.'test' | 'hallo', extraHttpRequestParams?: any ) : ng.IHttpPromise<string> {
...
}

Swagger-codegen version

editor.swagger.io

Swagger declaration file content or url

parameters:
        - in: query
          name: foo
          enum:
            - 'test'
            - 'hallo'
          description: image
          required: true
          type: string

Command line used for generation

editor.swagger.io

Steps to reproduce

• create a method with an enum parameter
• generate typescript-angularjs client

Related issues/PRs

Suggest a fix/enhancement

The generated method header should look like this:

public test (foo: 'test' | 'hallo', extraHttpRequestParams?: any ) : ng.IHttpPromise<string> {
...
}

Start with the TypeScript AngularJS generator templates and the rendering path for enum query parameters. Reproduce the example from the issue, then trace how enum values become the generated method header and model type. Done means the generated header uses valid TypeScript string-literal unions as shown and the client remains valid.