'Get configurations for mirrors to connect to.
.. note:: This is a `classmethod`.
:param conf_file: Path to a configuration file containing which
contains the server list.
:type conf_file: str
:return: `tag`, `test url`, and `update url` of the servers listed in
the configuration file.
Definition of the dictionary returned:
Key       Value
tag       `Tag` string of a specified server.
label     Name of a specified server.
test_url  `URL` to test the connection to a server.
update    `URL` containing the directory to get latest hosts                          data file.
:rtype: dict'

@classmethod
def set_network(cls, conf_file='network.conf'):

    conf = ConfigParser.ConfigParser()
    conf.read(conf_file)
    mirrors = []
    for sec in conf.sections():
        mirror = {'tag': sec, 'label': conf.get(sec, 'label'), 'test_url': conf.get(sec, 'server'), 'update': conf.get(sec, 'update')}
        mirrors.append(mirror)
    return mirrors
