按照yii官网文档通过composer安装yii2.*框架报错 Could not open file: composer.phar

将官方文档安装框架命令（linux版）：

php composer.phar global require "fxp/composer-asset-plugin:~1.2.0"

php composer.phar create-project yiisoft/yii2-app-basic basic 2.0.12

php composer.phar create-project yiisoft/yii2-app-advanced advanced 2.0.12

修改为（windows版）：

composer global require "fxp/composer-asset-plugin:~1.2.0"

composer create-project yiisoft/yii2-app-basic basic 2.0.12

composer create-project yiisoft/yii2-app-advanced advanced 2.0.12