updated to include version of opdk prior to 4.17.01

gce-properties.yml

diff --git a/gce-properties.yml b/gce-properties.yml
index 20fe939..71f1199 100644
--- a/gce-properties.yml
+++ b/gce-properties.yml
@@ -1,7 +1,8 @@
 ---
 credentials_file: ~/.ansible/access/default-service-account.json
 machine_type: 'n1-standard-1'
-image: 'centos-7-v20170918'
+#image: 'centos-7-v20170918'
+image: 'centos-6-v20170918'
 zone: 'us-east1-b'
 host_prefix: 'cf'
 labels: