Gets a person by client ID and email address.

def get(self, client_id=None, email_address=None):
        """Gets a person by client ID and email address."""
        params = {"email": email_address or self.email_address}
        response = self._get("/clients/%s/people.json" %
                             (client_id or self.client_id), params=params)
        return json_to_py(response)