Add iputils-arping package for quantum l3 agent.

This is for Ubuntu only since arping command is
packeged in iputils on Fedora, which is already
in files/rpms/quantum.

Change-Id: I8318929fb35a12e0fb7a6a148d8ef0554cf3bc30
Signed-off-by: Tomoe Sugihara <tomoe@midokura.com>
diff --git a/files/apts/quantum b/files/apts/quantum
index 39f4561..64fc1bf 100644
--- a/files/apts/quantum
+++ b/files/apts/quantum
@@ -1,6 +1,7 @@
 ebtables
 iptables
 iputils-ping
+iputils-arping
 mysql-server #NOPRIME
 sudo
 python-boto