fix typo in variable name

Author: weallwegot

post_commit_hook_template.py

@@ -27,7 +27,7 @@ def main():
  tweet += " " + arg
 
  api = get_api(cfg)
- status = api.update_status(status=tweet_str)
+ status = api.update_status(status=tweet)
 
 if __name__ == "__main__":
  main()