Schemas generated from Serializers will now be added to the `definitions` section by default, and used as `$ref` objects where needed.
The Schema definition name is based on the serializer class name, and can be overriden by specifying a `__ref_name__` property on the Serializer. If this property is set to None, the schema will not be added to `definitions` and will be forced inline.
Closes#6, #7.
Cristi Vîjdea
h-hirokawa