def create_signed_value(name, value):
    """Encode `name` and `value` string into byte-string using 'utf-8'
        encoding settings, convert value into base64. Return signed value as
        string,::

          <base64-encoded-value>|<timestamp>|<signature>

        <signature> is generated using a ``secret``, ``name``, base64 encoded 
        ``value`` and timestamp-in-seconds.
        """
