use TEST_MACHINE envv to pass the target IP
use TEST_MACHINE envv to pass the target IP

TEST_MACHINE is now the name of the variable to pass the IP of the
libvirt node.

Change-Id: Ic125477993760c78180ec5f8c3741a4f5d5e6b22

goneri/dci-control-server,goneri/dci-control-server,goneri/dci-control-server,enovance/dci-control-server,goneri/dci-control-server,enovance/dci-control-server,redhat-cip/dci-control-server,redhat-cip/dci-control-server