[BUG] Schema not parsed correctly in some cases when response is Array

[fryette]

Describe the bug
When schema has next part for request

"responses": {
          "200": {
            "description": "An array of all currencies",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/Currency"
                }
              }
            }
          },
          "401": {
            "$ref": "#/components/responses/UnauthorizedError"
          }
        }
      }

where the currency is:

 "Currency": {
        "type": "array",
        "items": {
          "type": "string"
        },
        "example": [
          "USD",
          "EUR"
        ]
      }

build failed.
Seems we need to handle that case when schema is defined together with items