uncloud cli converted to argparse

uncloud/host/main.py

@@ -1,6 +1,7 @@
 import argparse
 import multiprocessing as mp
 import time
+
 from uuid import uuid4
 
 from uncloud.common.request import RequestEntry, RequestType
@@ -12,6 +13,9 @@ from os.path import join as join_path
 
 from . import virtualmachine, logger
 
+arg_parser = argparse.ArgumentParser('host', add_help=False)
+arg_parser.add_argument('--hostname', required=True)
+
 
 def update_heartbeat(hostname):
     """Update Last HeartBeat Time for :param hostname: in etcd"""