Correct the mapping of nodes and roles in virtual deploy

Correct the mapping of nodes and roles in virtual deploy

JIRA: DAISY-56

Now the roles are assigned to nodes randomly, because the function
'add_hosts_interface' in tempest.py just uses zip to map the
host's name to the host.

libvirt_utils.py: get mac addresses from VM
environment.py: save the mac addresses
daisy_server.py: write a new deploy.yml which contains the mac addresses
    and copy the file to daisy server
get_conf.py: get mac addresses from the new deploy.yml
tempest.py: assigned roles to nodes when the mac addresses matched
controller.xml: increase the RAM to make difference with computer nodes
deploy.sh: apply this change to bash script

Change-Id: Ia61b60d39d319c5d01e3505727fafc63a0585858
Signed-off-by: Alex Yang <yangyang1@zte.com.cn>