OpenAPIs sample: petstore-with-external-docs.json is not processed properly in 0.5 or 0.6.

[ckriley]

Definition is found at: https://github.com/OAI/OpenAPI-Specification/blob/master/examples/v2.0/json/petstore-with-external-docs.json

The following definition is not processed properly:

"Pet": {
"type": "object",
"allOf": [
{
"$ref": "#/definitions/NewPet"
},
{
"required": [
"id"
],
"properties": {
"id": {
"type": "integer",
"format": "int64"
}
}
}
]
}