Add ability to set reauthentication_auth_method option

To allow heat to reauthenticate using trusts for long running tasks
this option is needed to be set to 'trusts'.

Change-Id: I48c36487aee5cde5fd3cf139766038fecd7e3f28
Related-Prod: https://mirantis.jira.com/browse/PROD-27017
6 files changed