change from puppetlabs xenial image to ubuntu default
diff --git a/.kitchen.yml b/.kitchen.yml
index af28a28..846b372 100644
--- a/.kitchen.yml
+++ b/.kitchen.yml
@@ -33,7 +33,7 @@
   - name: ubuntu1664
     driver:
       box: ubuntu/xenial64
-      box_url: https://atlas.hashicorp.com/puppetlabs/boxes/ubuntu-16.04-64-nocm/versions/1.0.0/providers/virtualbox.box
+      box_url: https://cloud-images.ubuntu.com/xenial/current/xenial-server-cloudimg-amd64-vagrant.box
   - name: apache-trusty
     driver:
       box: apache/trusty64