Session hooks are not called

[FelixSchwarz]

When I create an OpenAPI client like this:

api = OpenAPI(spec, use_session=True, session_factory=MySession)

then any hooks that MySession might use are not called.

The bug is caused because paths.py calls .prepare() on the request so the session never comes into play:

openapi3/openapi3/paths.py

Line 344 in e6cbc94

result = session.send(self._request.prepare(), verify=verify)

The correct approach is to call session.prepare_request(self._request).