Ref Parameters are ignored

[louisbranch]

When a query parameter is a reference, the code isn't generated for it:

      parameters:
      - $ref: '#/parameters/LabelFilter'
...

parameters:
  LabelFilter:
    name: label
    in: query
    description: |
      Filter results to only include those that have this label.
    type: string
    format: label
    pattern: ^[a-z0-9][a-z0-9\-\_]{1,128}$

Copying the definition works:

      - name: label
        in: query
        description: |
          Filter results to only include those that have this label.
        type: string
        format: label
        pattern: ^[a-z0-9][a-z0-9\-\_]{1,128}$