tools: Remove unused imports.

tools/test-help-documentation.py

@@ -4,16 +4,12 @@ import os
 import sys
 import subprocess
 
-import time
-
 ZULIP_PATH = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 
 # check for the venv
 from lib import sanity_check
 sanity_check.check_venv(__file__)
 
-import requests
-
 parser = argparse.ArgumentParser()
 parser.add_argument('--force', default=False,
                     action="store_true",