Accept any callable as the schema

Rather than explicitly depending on the schema package, I can just accept any callable. This is more flexible, and makes it possible to do custom processing on the whole parameter dictionary at once (schema only looks at one key at a time). I can continue to use schema like so:

@parametrize_From_file(
        schema=Schema({
            object: object
        }).validate
)

kalekundert / parametrize_from_file

Accept any callable as the schema #1