Handling allOf for Dog and Cat types of Pet

[cfaurer]

Extended Pet example to include Cat and Dog using allOf example from here: https://github.com/OAI/OpenAPI-Specification/blob/master/versions/2.0.md

Get the following error:

`python swagger_to_uml.py swagger.json > swagger.puml
required key "type" not found in dictionary {"description": "A representation of a cat", "allOf": [{"$ref": "#/definitions/Pet"}, {"type": "object", "properties": {"huntingSkill": {"type": "string", "description": "The measured skill for hunting", "default": "lazy", "enum": ["clueless", "lazy", "adventurous", "aggressive"]}}, "required": ["huntingSkill"]}]}
Traceback (most recent call last):
File "swagger_to_uml.py", line 380, in
sw = Swagger.from_file(input_file_name)
File "swagger_to_uml.py", line 367, in from_file
return Swagger.from_dict(loader(fd))
File "swagger_to_uml.py", line 357, in from_dict
definitions = [Definition.from_dict(name, definition) for name, definition in d.get('definitions',{}).items()]
File "swagger_to_uml.py", line 357, in
definitions = [Definition.from_dict(name, definition) for name, definition in d.get('definitions',{}).items()]
File "swagger_to_uml.py", line 204, in from_dict
type=d['type'],
KeyError: 'type'

Modified swagger attached

swagger.json.txt