Composer设置忽略版本匹配

最近使用composer安装时发现提示php的版本不匹配。执行composer install遇到错误：Your requirements could not be resolved to an installable set of packages. 这是因为不匹配composer.json要求的版本。

完整错误如下：

[PHP]

vagrant@homestead:/usr/share/nginx/html/laravel-1$ sudo composer install
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - Installation request for doctrine/instantiator 1.0.3 -> satisfiable by doctrine/instantiator[1.0.3].
    - doctrine/instantiator 1.0.3 requires php ~5.3 -> your PHP version (7.0.3) does not satisfy that requirement.
  Problem 2
    - doctrine/instantiator 1.0.3 requires php ~5.3 -> your PHP version (7.0.3) does not satisfy that requirement.
    - phpunit/phpunit-mock-objects 2.3.0 requires doctrine/instantiator ~1.0,>=1.0.1 -> satisfiable by doctrine/instantiator[1.0.3].
    - Installation request for phpunit/phpunit-mock-objects 2.3.0 -> satisfiable by phpunit/phpunit-mock-objects[2.3.0].

提示我的PHP 7版本太高，不符合composer.json需要的版本，但是在PHP 7下应该也是可以运行的，composer可以设置忽略版本匹配，命令是：

composer install --ignore-platform-reqs

or

composer update --ignore-platform-reqs

再次执行composer命令可以正常安装包了。