Use daemon threads

Otherwise they can prevent exiting on timeout which confuses testr.

Change-Id: I239ab46f44fd09fe6b69fb70fdf4043e3c1daa67
Reviewed-on: https://review.openstack.org/35321
Reviewed-by: Monty Taylor <mordred@inaugust.com>
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Approved: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins
4 files changed