Parse instance configuration and perform minimal verification

def _get_instance_params(cls, instance):
        """
        Parse instance configuration and perform minimal verification
        """
        url = instance.get("url")
        if url is None:
            raise ConfigurationError("You must specify a url for your instance in `conf.yaml`")
        username = instance.get("username")
        password = instance.get("password")
        ssl_params = None
        if url.startswith("ldaps"):
            ssl_params = {
                "key": instance.get("ssl_key"),
                "cert": instance.get("ssl_cert"),
                "ca_certs": instance.get("ssl_ca_certs"),
                "verify": is_affirmative(instance.get("ssl_verify", True)),
            }
        custom_queries = instance.get("custom_queries", [])
        tags = list(instance.get("tags", []))
        tags.append("url:{}".format(url))

        return url, username, password, ssl_params, custom_queries, tags