使用 EasyWeChat Laravel 5 的拓展包: overtrue/Laravel-wechat 报错？

vagrant@homestead:~/Code/larabbs$ composer require "overtrue/laravel-wechat:~4.0"
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)

[Composer\Downloader\TransportException]
The "https://packagist.laravel-china.org/p/phpu...
c5dfe4977c1da02830b08f66d67babe5621ed4d824f.json" file could not be downloaded: p
hp_network_getaddresses: getaddrinfo failed: Temporary failure in name resolution
failed to open stream: php_network_getaddresses: getaddrinfo failed: Temporary fa
ilure in name resolution

require [--dev] [--prefer-source] [--prefer-dist] [--no-progress] [--no-suggest] [--no-update] [--no-scripts] [--update-no-dev] [--update-with-dependencies] [--update-with-all-dependencies] [--ignore-platform-reqs] [--prefer-stable] [--prefer-lowest] [--sort-packages] [-o|--optimize-autoloader] [-a|--classmap-authoritative] [--apcu-autoloader] [--] []...

vagrant@homestead:~/Code/larabbs$