It may be useful to be able to execute a command without a retry.
A good use case is provider in [1], where the keystone_user resource try
to get an user by fetching it. It is expected to fail when the user is
absent. With the current implementation, it will takes 60 seconds for
the provider to give up on the user.
[1] https://review.openstack.org/299301
Closes-Bug: #1563898
Change-Id: I5b334e3ffd26df4ba8584d77a5e41b56e73536c8