Hook: prepare a commit message.

def prepare_commit_msg_hook(argv):
    """Hook: prepare a commit message."""
    options = get_options()
    # Check if the repo has a configuration repo
    options.update(_read_local_kwalitee_configuration())

    _prepare_commit_msg(argv[1],
                        _get_git_author(),
                        _get_files_modified(),
                        options.get('template'))
    return 0