create CloudFormation outputs and enable 'Fn::GetAtt' to work.

moto/sns/models.py

@@ -8,6 +8,7 @@ from moto.core import BaseBackend
 from moto.core.utils import iso_8601_datetime
 from moto.sqs.models import sqs_backend
 from .utils import make_arn_for_topic, make_arn_for_subscription
+from boto.exception import BotoServerError
 
 DEFAULT_ACCOUNT_ID = 123456789012
 
@@ -33,6 +34,13 @@ class Topic(object):
             subscription.publish(message, message_id)
         return message_id
 
+    def get_cfn_attribute(self, attribute_name):
+        if attribute_name == 'TopicName':
+            return self.name
+        raise BotoServerError(400,
+                              'Bad Request',
+                              'Template error: resource {0} does not support attribute type {1} in Fn::GetAtt')
+
 
 class Subscription(object):
     def __init__(self, topic, endpoint, protocol):