input: Write a python function to clone a remote Git repository using GitPython.
  assert clone_repository("https://github.com/username/repo.git") is not None
output: def clone_repository(repo_url):
      from git import Repo
      import tempfile
  
      try:
          temp_dir = tempfile.mkdtemp()
          Repo.clone_from(repo_url, temp_dir)
          return temp_dir
      except Exception as e:
          return None