Py3: Fix encoding in _verify_topics method

Change-Id: I0f75ca4505acfd7840cde7d76174bd8a32354880

monasca_log_api/healthcheck/kafka_check.py

@@ -16,6 +16,7 @@ import collections
 
 from monasca_common.kafka_lib import client
 from oslo_log import log
+from six import PY3
 
 from monasca_log_api import conf
 
@@ -72,6 +73,9 @@ class KafkaHealthCheck(object):
     def _verify_topics(self, kafka_client):
         topics = CONF.kafka_healthcheck.kafka_topics
 
+        if PY3:
+            topics = tuple(topic.encode('utf-8') for topic in topics)
+
         for t in topics:
             # kafka client loads metadata for topics as fast
             # as possible (happens in __init__), therefore this