Write volume API version into clouds.yaml

We're trying to get things to use volume v2 by default. devstack already
deploys a v2 endpoint. Tell clouds.yaml that this devstack cloud is a v2
enabled cloud.

Change-Id: I6f792ce65153389aa1ee133e9bd363c394b28534
Closes-Bug: 1467589
diff --git a/tools/update_clouds_yaml.py b/tools/update_clouds_yaml.py
index 3a364fe..eb7265f 100755
--- a/tools/update_clouds_yaml.py
+++ b/tools/update_clouds_yaml.py
@@ -36,6 +36,7 @@
         self._cloud_data = {
             'region_name': args.os_region_name,
             'identity_api_version': args.os_identity_api_version,
+            'volume_api_version': args.os_volume_api_version,
             'auth': {
                 'auth_url': args.os_auth_url,
                 'username': args.os_username,
@@ -82,6 +83,7 @@
     parser.add_argument('--os-cloud', required=True)
     parser.add_argument('--os-region-name', default='RegionOne')
     parser.add_argument('--os-identity-api-version', default='3')
+    parser.add_argument('--os-volume-api-version', default='2')
     parser.add_argument('--os-cacert')
     parser.add_argument('--os-auth-url', required=True)
     parser.add_argument('--os-username', required=True)