去掉yii2 mongodb扩展依赖

composer.json

@@ -24,12 +24,10 @@
   "minimum-stability": "stable",
   "require": {
     "php": ">=5.4.0",
-    "ext-mongodb": "*",
     "yiisoft/yii2-swiftmailer": "2.0.7",
     "yiisoft/yii2": ">=2.0.15" ,
     "fancyecommerce/fec":">=1.1.5.0",
     "fancyecommerce/fec_admin":">=1.3.9.2",
-    "yiisoft/yii2-mongodb": "~2.1.7",
     "ramsey/uuid": "*",
     "facebook/graph-sdk": "*",
     "hightman/xunsearch": "*@beta"