compser报错：Your requirements could not be resolved to an installable set of packages.

compser报错：Your requirements could not be resolved to an installable set of packages.

是因为php版本的缘故，导致包安装不上，报错，这里解决方法是，直接忽略版本，
运行命令

composer install --ignore-platform-reqs

或者

composer update --ignore-platform-reqs

安装某个包的时候运行命令

composer require laravel/laravel