Use volume v3 API in clouds.yaml by default

Volume API v2 has been deprecated for a long time.
There is no reason to use volume v2 in clouds.yaml by default.

This commit also drops "--os-identity-api-version 3" from
write_clouds_yaml in functions -common as "3" is the default value
of tools/update_clouds_yaml.py. They are hardcoded in DevStack
so there is no reason to pass it.

Change-Id: Ie84026a3d19f7711fc781b7012355096c7ff6b5a

Author: amotoki

functions-common

@@ -92,7 +92,6 @@ function write_clouds_yaml {
         --file $CLOUDS_YAML \
         --os-cloud devstack \
         --os-region-name $REGION_NAME \
-        --os-identity-api-version 3 \
         $CA_CERT_ARG \
         --os-auth-url $KEYSTONE_SERVICE_URI \
         --os-username demo \
@@ -104,7 +103,6 @@ function write_clouds_yaml {
         --file $CLOUDS_YAML \
         --os-cloud devstack-alt \
         --os-region-name $REGION_NAME \
-        --os-identity-api-version 3 \
         $CA_CERT_ARG \
         --os-auth-url $KEYSTONE_SERVICE_URI \
         --os-username alt_demo \
@@ -116,7 +114,6 @@ function write_clouds_yaml {
         --file $CLOUDS_YAML \
         --os-cloud devstack-admin \
         --os-region-name $REGION_NAME \
-        --os-identity-api-version 3 \
         $CA_CERT_ARG \
         --os-auth-url $KEYSTONE_SERVICE_URI \
         --os-username admin \

tools/update_clouds_yaml.py

@@ -83,7 +83,7 @@ def main():
     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-volume-api-version', default='3')
     parser.add_argument('--os-cacert')
     parser.add_argument('--os-auth-url', required=True)
     parser.add_argument('--os-username', required=True)