我第一次尝试使用 composer 安装 Laravel。
按照https://laravel.com/docs/5.1上的文档，我尝试使用命令来完成sudo composer global require "laravel/installer"。
我得到的输出粘贴在下面：
Changed current directory to /home/israel/.composer
Using version ^2.0 for laravel/installer
./composer.json has been created
Loading composer repositories with package information
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.
Problem 1
- laravel/installer v2.0.1 requires ext-zip * -> the requested PHP extension zip is missing from your system.
- laravel/installer v2.0.0 requires ext-zip * -> the requested PHP extension …