Errors on schema validation should print full path to invalid field

[andrewsardone]

If I receive the following validation error:

class mismatch for id: expected [<type 'str'>, <type 'unicode'>], 1 has class int

I'm not sure where in my document its referring to the id field. It'd be great if the output indicated, say, the full JSON path of the field (e.g., certificate.parsed.certificate_policies.id)

I could be using the tool incorrectly, so bear with me 😄