Use standard get_or_create_role to find role

The openstack role list command doesn't include any identity API version
information and so will fail when running purely with v3. We could add
this information to the command however we already have a function that
does what swift requires so we should use it.

Change-Id: I5d5417eaed432760bfb97cf35bd76a0919c6004d

Author: Jamie Lennox

lib/swift

@@ -610,7 +610,7 @@ function create_swift_accounts {
 
     KEYSTONE_CATALOG_BACKEND=${KEYSTONE_CATALOG_BACKEND:-sql}
 
-    local another_role=$(openstack role list | awk "/ anotherrole / { print \$2 }")
+    local another_role=$(get_or_create_role "anotherrole")
 
     # NOTE(jroll): Swift doesn't need the admin role here, however Ironic uses
     # temp urls, which break when uploaded by a non-admin role