With latest localstack image running in Docker, when publishing a message to a non-existent SNS topic no error is thrown.  This differs from AWS.
import ast
import json
import logging
import requests
import uuid
import xmltodict
import six
from requests.models import Response
from six.moves.urllib import parse as urlparse
from localstack.utils.aws import aws_stack
from localstack.utils.common import short_uid, to_str
from localstack.services.awslambda import lambda_api
from localstack.services.generic_proxy import ProxyListener
SNS_SUBSCRIPTIONS = {}
LOGGER = logging.getLogger(__name__)
class ProxyListenerSNS(ProxyListener):