Include instructions for adding tests
Include instructions for adding tests

Include instructions in CONTRIBUTING for how to include tests
for a newly introduced openstack service

Connects https://github.com/rcbops/rpc-openstack/issues/1800

mancdaz/rpc-openstack,galstrom21/rpc-openstack,hughsaunders/rpc-openstack,cfarquhar/rpc-openstack,mancdaz/rpc-openstack,BjoernT/rpc-openstack,rcbops/rpc-openstack,jacobwagner/rpc-openstack,jacobwagner/rpc-openstack,hughsaunders/rpc-openstack,robb-romans/rpc-openstack,cloudnull/rpc-openstack,rcbops/rpc-openstack,git-harry/rpc-openstack,shannonmitchell/rpc-openstack,shannonmitchell/rpc-openstack,cloudnull/rpc-openstack,git-harry/rpc-openstack,BjoernT/rpc-openstack,robb-romans/rpc-openstack,prometheanfire/rpc-openstack,major/rpc-openstack,major/rpc-openstack,galstrom21/rpc-openstack,cfarquhar/rpc-openstack,prometheanfire/rpc-openstack