Components that are references to other components do not serialize properly.

This does not work properly.
```
openapi: 3.0.0
info:
  title: blag
  version: 1.0.0
paths:
  /: 
    get:
      responses:
        200:
          $ref: '#/components/responses/bob'
components:
  responses:
    bob:
      $ref: '#/components/responses/otherbob'
    otherbob:
      description: ok
```