Add python-netaddr module to ansible to address the build failure

Change-Id: I0f0990c33535379a44008855979a4cacc37fdeab
diff --git a/ansible/roles/common/defaults/main.yml b/ansible/roles/common/defaults/main.yml
index 7be66d2..63c3a06 100644
--- a/ansible/roles/common/defaults/main.yml
+++ b/ansible/roles/common/defaults/main.yml
@@ -17,6 +17,7 @@
   - python-nose
   - python-flake8
   - python-scapy
+  - python-netaddr
 #  - python-libpcap
 
 obsolete_services: