Remove delete stubs in test_resource_tracker
Remove delete stubs in test_resource_tracker

The resource tracker never calls ComputeNode.destroy() and therefore
never calls nova.db.compute_node_delete(). However, the base test case
class in test_resource_tracker.py was stubbing this out for some reason.

Change-Id: I14083850974202ead38dea996c42456155814219

Juniper/nova,rahulunair/nova,cloudbase/nova,mahak/nova,jianghuaw/nova,mahak/nova,klmitch/nova,Juniper/nova,gooddata/openstack-nova,bigswitch/nova,vmturbo/nova,vmturbo/nova,jianghuaw/nova,sebrandon1/nova,mikalstill/nova,hanlind/nova,jianghuaw/nova,openstack/nova,mahak/nova,klmitch/nova,rahulunair/nova,mikalstill/nova,rajalokan/nova,Juniper/nova,jianghuaw/nova,phenoxim/nova,gooddata/openstack-nova,gooddata/openstack-nova,rajalokan/nova,vmturbo/nova,phenoxim/nova,vmturbo/nova,rahulunair/nova,openstack/nova,Juniper/nova,cloudbase/nova,hanlind/nova,klmitch/nova,gooddata/openstack-nova,sebrandon1/nova,sebrandon1/nova,bigswitch/nova,hanlind/nova,rajalokan/nova,alaski/nova,alaski/nova,cloudbase/nova,klmitch/nova,mikalstill/nova,openstack/nova,rajalokan/nova