Use nproc puppet apply processes when testing
Use nproc puppet apply processes when testing

Puppet apply is single threaded and slow. We are testing many puppet
applies in noop mode so it should be safe to run them in parallel using
the number of cpus available to us. Make it so.

Change-Id: I66250d21258de7791e4f5fc0b013100efae63603

noorul/os-project-config,osrg/project-config,anbangr/osci-project-config,openstack-infra/project-config,coolsvap/project-config,citrix-openstack/project-config,osrg/project-config,open-switch/infra_project-config,open-switch/infra_project-config,citrix-openstack/project-config,anbangr/osci-project-config,coolsvap/project-config,dongwenjuan/project-config,Tesora/tesora-project-config,openstack-infra/project-config,noorul/os-project-config,dongwenjuan/project-config,Tesora/tesora-project-config