Implement the deployment script with python

Implement the deployment script with python

1. deploy.py: control the work flow of the deployment
2. daisy_server.py: maintain the ssh connection with daisy server
     and execute ssh commands
3. environment.py: create/find/delete the nodes/vms, install operating system
     and openstack on nodes
4. libvirt_utils.py: deal with the vm templates and call virsh commands
5. utils.py: some common functions such as file/directory/bash operation

Change-Id: I1caa4b0b3118665e15410e8f02bcb6473e5a530b
Signed-off-by: Alex Yang <yangyang1@zte.com.cn>