[typescript-node] Not generating optional model members correctly.

Description

typescript-node is not producing models with optional fields where they ought to be. All fields are created as required.

Swagger-codegen version

2.2.3

Swagger declaration file content or url

  Project:
    type: object
    properties:
      created:
        $ref: "#/definitions/UserTouchTime"
      id:
        type: string
        readOnly: true
      lastModified:
        $ref: "#/definitions/UserTouchTime"
      name:
        type: string
    required:
      - name

This is the model that was generated:

export class Project {
    'created': UserTouchTime;
    'id': string;
    'lastModified': UserTouchTime;
    'name': string;
}

However, everything except name should be optional (have a ? after the property name).

Command line used for generation

java -jar swagger-codegen-cli-2.2.3.jar generate -l typescript-node -i c:/Users/abrick/src/vt.meta-swagger/swagger.yaml -o foo

Steps to reproduce

Run the above command.

Related issues/PRs

Can't find one.

Suggest a fix/enhancement

I don't see where in the code this would be set, but I notice that in the Mustache template, it just uses the name property. It probably also needs to have a required property that determines if a ? should be appended.

Start with the typescript-node Mustache model template and reproduce the issue using the Swagger declaration and generation command in the report. Update the generated model so only fields listed under required lack a question mark, then compare the output with the expected Project example.