Support boolean schemas

[jcklie]

JSON schema has a niche case where are allowed to just consist of a boolean 1. Therefore, this is a valid schema:

{
    "type": "object",
    "properties": {
        "foo": {
          "type": "array",
    	  "items": true  
        },
        "bar": false
    }
}

I encountered some schemas using this in real life that used this feature and fail parsing with this package. I see two solutions to this problem: extending the union wherever there is a schema used, e.g. turn all Union[Ref, Schema] into Union[Ref, Schema, bool] or make schema itself a union of Schema and Bool and rename the existing schema to something like JsonSchema. I hacked it for myself to use the former solution.

[mike-oakley]

Hi @jcklie - thanks for reaching out! Happy to accept a contribution for this, probably the latter solution (make schema itself a union of Schema and Bool and rename the existing schema to something like JsonSchema) would be preferable in my mind to reduce the number of places that need updating?

[rafalkrupinski]

i would find it confusing, if there were both Schema and JsonSchema types in the project.