linux 使用composer 安装yii2框架报错

使用 composer create-project yiisoft/yii2-app-basic yii2
报下面错误，
Running composer as root/super user is highly discouraged as packages, plugins and scripts cannot always be trusted
Installing yiisoft/yii2-app-basic (2.0.8)

• Installing yiisoft/yii2-app-basic (2.0.8)
  Loading from cache

Created project in yii2
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

• yiisoft/yii2 2.0.8 requires bower-asset/jquery 2.2.@stable | 2.1.@stable | 1.11.*@stable -> no matching package found.

• yiisoft/yii2 2.0.7 requires bower-asset/jquery 2.2.@stable | 2.1.@stable | 1.11.*@stable -> no matching package found.

• yiisoft/yii2 2.0.6 requires bower-asset/jquery 2.1.@stable | 1.11.@stable -> no matching package found.

• yiisoft/yii2 2.0.5 requires bower-asset/jquery 2.1.@stable | 1.11.@stable -> no matching package found.

• Installation request for yiisoft/yii2 >=2.0.5 -> satisfiable by yiisoft/yii2[2.0.5, 2.0.6, 2.0.7, 2.0.8].

Potential causes:

• A typo in the package name

• The package is not available in a stable-enough version according to your minimum-stability setting
  see https://getcomposer.org/doc/04-schema.md#minimum-stability for more details.

Read https://getcomposer.org/doc/articles/troubleshooting.md for further common problems.

登陆的是root权限；
是什么原因，怎么解决；