Switching Vagrant box to Xenial

Change-Id: If874cace314e0a1a4e9934a8973e197a656c5c86
diff --git a/ansible/roles/common/defaults/main.yml b/ansible/roles/common/defaults/main.yml
index c97c39d..82f5092 100644
--- a/ansible/roles/common/defaults/main.yml
+++ b/ansible/roles/common/defaults/main.yml
@@ -6,6 +6,7 @@
   - debian-keyring
   - debian-archive-keyring
   - python-dev
+  - kafkacat
   - libssl-dev
   - libffi-dev
   - libpcap-dev