Lists all repos on ``/etc/opkg/*.conf``

    CLI Example:

    .. code-block:: bash

       salt '*' pkg.list_repos

def list_repos(**kwargs):  # pylint: disable=unused-argument
    '''
    Lists all repos on ``/etc/opkg/*.conf``

    CLI Example:

    .. code-block:: bash

       salt '*' pkg.list_repos
    '''
    repos = {}
    regex = re.compile(REPO_REGEXP)
    for filename in os.listdir(OPKG_CONFDIR):
        if not filename.endswith(".conf"):
            continue
        with salt.utils.files.fopen(os.path.join(OPKG_CONFDIR, filename)) as conf_file:
            _read_repos(conf_file, repos, filename, regex)
    return repos