有一个问题，帮忙解决下
[Composer\Repository\InvalidRepositoryException] No valid bower.json was found in any branch or tag of https://github.com/RobinHerbots/Inputmask.git, could not load a package from it.
你这个我也没遇到过，看着像是composer加载的时候出现问题。你可以试试下面的语句
composer self-update composer global require "fxp/composer-asset-plugin:^1.3.1"
试试看更新了composer之后会不会出现，我之前在安装YII2的时候没有更新也会出问题，记得翻墙或者切换国内镜像
参看这个文章解决下试试：
http://www.cuidmm.cn/archives/458
http://www.fecshop.com/topic/412