Clean up imports

Make several imports more specific to reduce redundant code imports and
improve memory utilization.

node-daemon/pvcnoded/VMInstance.py

@@ -20,16 +20,13 @@
 #
 ###############################################################################
 
-import os
-import sys
 import uuid
-import socket
 import time
-import threading
 import libvirt
-import kazoo.client
 import json
 
+from threading import Thread
+
 import pvcnoded.log as log
 import pvcnoded.zkhandler as zkhandler
 import pvcnoded.common as common
@@ -138,7 +135,7 @@ class VMInstance(object):
 
             # Perform a management command
             self.logger.out('Updating state of VM {}'.format(self.domuuid), state='i')
-            state_thread = threading.Thread(target=self.manage_vm_state, args=(), kwargs={})
+            state_thread = Thread(target=self.manage_vm_state, args=(), kwargs={})
             state_thread.start()
 
     # Get data functions