[kafka] Bump kafka-python to 1.3.1 (#3097)

Another take on #2863 because I deleted the original branch

Author: jeffwidman

requirements.txt

@@ -44,7 +44,7 @@ pyro4==4.35 # required by adodbapi
 httplib2==0.9
 
 # checks.d/kafka_consumer.py
-kafka-python==1.2.5
+kafka-python==1.3.1
 kazoo==2.2.1
 
 # checks.d/postgres.py