Support for nullable types on operation parameters

[ikitommi]

{ "type": ["string", "null"] } is a valid JSON Schema type definition and as Swagger Schema references the schema directly (https://github.com/reverb/swagger-spec/blob/master/schemas/v2.0/schema.json#L489) - it works and is shown on the swagger-ui. It does not work when added as operation parameters: https://github.com/reverb/swagger-spec/blob/master/schemas/v2.0/schema.json#L393-L396.

It could and should?

sample working swagger.json with nullable field on the schema properties:

https://gist.githubusercontent.com/ikitommi/7de56d1a89534bbbbfaa/raw/3c96da810b0b836e617907f92578ae4f27f79c8c/swagger2.json

[webron]

For 2.0, it can't and shouldn't. Keep in mind the source of truth is the spec, not schema. Please follow #229.