'Required' in a schema that refs another schema doesn't render

[nahun]

Q	A
Bug or feature request?	Bug
Which Swagger/OpenAPI version?	3.0.0
Which Swagger-UI version?	3.6.0
How did you install Swagger-UI?	Run index.html in browser
Which browser & version?	Latest Chrome
Which operating system?	Ubuntu 16.04

Demonstration API definition

openapi: 3.0.0
info:
  version: 1.0.0
  title: test

servers:
  - url: http://httpbin.org

paths:
  /anything:
    get:
      responses:
        '200':
          description: test
          content:
            application/json:
              schema:
                type: object
                properties:
                  name:
                    type: string
                    example: myname
                  jobs:
                    $ref: '#/components/schemas/listitems'
components:
  schemas:
    listitems:
      type: object
      required:
        - item
      properties:
        item:
          $ref: '#/components/schemas/item'
    item:
      type: string
      example: hi

Expected Behavior

The response schema should render all the properties

Current Behavior

It doesn't render much of anything

Possible Solution

Remove 'required' from the 'listitems' schema

Comments

This works in Swagger Hub without issues