Validator throws error for external references

[bhardwz]

I have a Swagger file which has external references.
Here is a snapshot of how I am calling out the external reference:

200:
      description: "Success"
      schema:
            $ref: "../../schema/car.yml#/definitions/services.CarMetadata"

Now Swagger Editor is not throwing error but, when I'm converting to swagger 3.0, I get this error:

---
- "malformed or unreadable swagger supplied"

This only comes up when I have external references in configuration.
Please look at this.