Description of authentication configuration options

Configuration option = Default value	Description
[DEFAULT]
auth_strategy = keystone	(StrOpt) The strategy to use for auth: keystone, noauth (deprecated), or noauth2. Both noauth and noauth2 are designed for testing only, as they do no actual credential checking. noauth provides administrative credentials regardless of the passed in user, noauth2 only does if 'admin' is specified as the username.