Minimum Stability Settings

Composer accepts these flags as minimum-stability settings. The default setting for minimum-stability if not provided is assumed to be stable, but you could define any of the flags down the hierarchy.

–stable (most stable)

– RC

– beta

– alpha

– dev (least stable)

 

使用 @dev 解决版本问题

"minimum-stability": "stable", "require": { "php": ">=5.4.0", "yiisoft/yii2": "*", "yiisoft/yii2-bootstrap": "*", "yiisoft/yii2-swiftmailer": "*", "kartik-v/yii2-grid": "@dev" },