Deprecation of keyschema and valueschema does not work when in subschema

[Moutix]

Used Cerberus version 1.3

Bug report / Feature request

Depreciation of the rule keyschema and valueschema does not work properly when in a subschema of valueschema or keyschema on itself:

This snipet will not work for instance:

schema = {
    "a": {
        'type': 'dict',
        'valueschema': {
            'type': 'dict',
            'keyschema': {
                'type': 'string',
            },
            'valueschema': {
                'type': 'string'
            },
        }
    }
}
cerberus.Validator(schema)

Output will be:

(BackEnd)  moutix@pistache ~/project/BackEnd (*feature/cerberus-upgrade) $ python testcerberus.py 
Traceback (most recent call last):
  File "testcerberus.py", line 36, in <module>
    cerberus.Validator(schema)
  File "/home/moutix/.virtualenvs/BackEnd/lib/python3.6/site-packages/cerberus/validator.py", line 181, in __init__
    self.schema = kwargs.get('schema', None)
  File "/home/moutix/.virtualenvs/BackEnd/lib/python3.6/site-packages/cerberus/validator.py", line 562, in schema
    self._schema = DefinitionSchema(self, schema)
  File "/home/moutix/.virtualenvs/BackEnd/lib/python3.6/site-packages/cerberus/schema.py", line 76, in __init__
    self.validate(schema)
  File "/home/moutix/.virtualenvs/BackEnd/lib/python3.6/site-packages/cerberus/schema.py", line 247, in validate
    self._validate(schema)
  File "/home/moutix/.virtualenvs/BackEnd/lib/python3.6/site-packages/cerberus/schema.py", line 263, in _validate
    raise SchemaError(self.schema_validator.errors)
cerberus.schema.SchemaError: {'a': [{'valuesrules': [{'keyschema': ['unknown rule'], 'valueschema': ['unknown rule']}]}]}

When setting with valuesrule, it will properly work:

import cerberus

schema = {
    "a": {
        'type': 'dict',
        'valuesrules': {
            'type': 'dict',
            'keysrules': {
                'type': 'string',
            },
            'valuesrules': {
                'type': 'string'
            },
        }
    }
}

[funkyfuture]

thanks for reporting.