composer.json 中php版本要求修改

composer.json

@@ -14,7 +14,7 @@
     },
     "minimum-stability": "dev",
     "require": {
-        "php": ">=5.4.0",
+        "php": ">=7.0",
         "yiisoft/yii2": "2.0.29",
         "yiisoft/yii2-bootstrap": "~2.0.6",
         "yiisoft/yii2-swiftmailer": "~2.0.6",