Ignore subrepos in .gitignore

Change-Id: Iadf9316595a195c6d66a09bd9686bd47b9821fec
diff --git a/.gitignore b/.gitignore
index 9a31323..11a3368 100644
--- a/.gitignore
+++ b/.gitignore
@@ -38,4 +38,12 @@
 *.bak
 
 # Maven repository
-repository
\ No newline at end of file
+repository
+
+# sub repos
+apps/aaa/
+apps/config/
+apps/igmp/
+apps/mcast/
+apps/olt/
+apps/vtn/