Support for JSON-RPC 1.0

[Frédéric Massart]

I would prefer using version 2.0 altogether, but some of the clients I'm using are still on 1.0. This should not make a big difference altogether, I think what needs to be done is:

1. Accepting to receive error: null for a valid request
2. Validate against the 1.0 schema
3. Indicate the version to use to the client

[Frédéric Massart]

Here is an example of a very hacky client, which sort of makes the request 1.0, and pretends the response is 2.0.

import json
from jsonrpcclient.clients.http_client import HTTPClient

class HTTPClient1_0(HTTPClient):

    def validate_response(self, response):
        data = json.loads(response.text)
        if 'error' in data and data['error'] is None:
            del data['error']
        data['jsonrpc'] = '2.0'
        response.text = json.dumps(data)

    def send(self, request, **kwargs):
        del request['jsonrpc']
        return super().send(request, **kwargs)

[Beau]

Probably won't add this, this is an implementation of the 2.0 spec.