不能处理node_module中含有的async语法，比如koa-bodyparser@4.x

[qingpinhuang]

D:\repositories\test\node_modules\koa-bodyparser\index.js:72
  return async function bodyParser(ctx, next) {
               ^^^^^^^^
SyntaxError: Unexpected token function
    at createScript (vm.js:56:10)
    at Object.runInThisContext (vm.js:97:10)
    at Module._compile (module.js:542:28)
    at Module._extensions..js (module.js:579:10)
    at Object.require.extensions.(anonymous function) [as .js] (D:\repositories\test\node_modules\babel-register\lib\node.js:152:7)
    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)
[nodemon] app crashed - waiting for file changes before starting...