我正在使用 Laravel 5.4 ， PHP 7.0.30 和 Ubuntu 。当我输入命令sudo composer require owen-it/laravel-auditing来安装Laravel-Auditing时，出现以下错误：
Your requirements could not be resolved to an installable set of packages.
Problem 1
- symfony/css-selector v4.1.4 requires php ^7.1.3 -> your PHP version (7.0.30) does not satisfy that requirement.
- symfony/css-selector v4.1.4 requires php ^7.1.3 -> your PHP version (7.0.30) does not satisfy that requirement.
- symfony/css-selector v4.1.4 requires php ^7.1.3 -> your PHP version (7.0.30) does not satisfy that requirement.
- Installation request for symfony/css-selector == 4.1.4.0 -> satisfiable by symfony/css-selector[v4.1.4].
Installation failed, reverting ./composer.json to its original content.
现在也不可以升级PHP版本。
请帮助！