项目显示async connect (url, opts) Unexpected identifier错误

[zhaoyao514]

项目完成后node index显示如下错误 mongodb已经配置好

PS E:\桌面文件\nodejs+monogdb\myblog> node index
E:\桌面文件\nodejs+monogdb\myblog\node_modules\mongolass\lib\index.js:31
async connect (url, opts) {
^^^^^^^
SyntaxError: Unexpected identifier
at createScript (vm.js:56:10)
at Object.runInThisContext (vm.js:97:10)
at Module._compile (module.js:542:28)
at Object.Module._extensions..js (module.js:579:10)
at Module.load (module.js:487:32)
at tryModuleLoad (module.js:446:12)
at Function.Module._load (module.js:438:3)
at Module.require (module.js:497:17)
at require (internal/module.js:20:19)
at Object. (E:\桌面文件\nodejs+monogdb\myblog\lib\mongo.js:2:19)