Bump up the count of workers for heat
Bump up the count of workers for heat

Looks like the workers is set to 0 which in heat is used
mainly for profiling/debugging and not really useful in
the devstack scenarios.
https://github.com/openstack/heat/blob/master/heat/common/wsgi.py#L286

Partial-Bug: #1412923
Change-Id: Iccf6aeffd461fdc1f78022cbda370be4b9573267

tianweizhang/devstack,eshnil2000/devstack,tianweizhang/devstack