sync_public_streams: Use option group for arguments.

bots/sync-public-streams

@@ -2,6 +2,7 @@
 import sys
 import os
 import logging
+import optparse
 import time
 import simplejson
 import subprocess
@@ -12,8 +13,6 @@ import zulip
 
 from typing import Set
 
-zulip_client = zulip.Client(client="ZulipSyncPublicStreamsBot/0.1")
-
 def fetch_public_streams():
     # type: () -> Set[str]
     public_streams = set()
@@ -56,6 +55,12 @@ if __name__ == "__main__":
     file_handler.setFormatter(formatter)
     logger.addHandler(file_handler)
 
+    parser = optparse.OptionParser()
+    parser.add_option_group(zulip.generate_option_group(parser))
+    (options, args) = parser.parse_args()
+
+    zulip_client = zulip.Client(client="ZulipSyncPublicStreamsBot/0.1")
+
     while True:
         time.sleep(15)
         public_streams = fetch_public_streams()