Add grenade.

Import from nebula github.  Add non-voting jobs to the immediately
relevant projects to facilitate iterating on the config while we
bootstrap it.

Change-Id: I8c603bf095019f43d070b3b28ec7ee5114cd9ccf
Reviewed-on: https://review.openstack.org/23209
Approved: James E. Blair <corvus@inaugust.com>
Reviewed-by: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins