Retrieve how long ago a file has been created.

    :param filename: name of the file

    >>> print created('/')             # doctest: +SKIP
    8 weeks ago

def created(filename):
    '''
    Retrieve how long ago a file has been created.

    :param filename: name of the file

    >>> print created('/')             # doctest: +SKIP
    8 weeks ago
    '''
    if isinstance(filename, file):
        filename = filename.name

    return duration(os.stat(filename)[stat.ST_CTIME])