Add kafka-onos to .gitignore

Change-Id: I35cd459006dbc8082a3a2047fcfb99e724fe4f06
diff --git a/.gitignore b/.gitignore
index 5d073c0..dcfbea3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -44,6 +44,7 @@
 apps/aaa/
 apps/config/
 apps/igmp/
+apps/kafka-onos/
 apps/mcast/
 apps/olt/
 apps/vtn/