我已经安装成功了，但输入gulp --watch后，还是报错gulp not found，而且我是下载您的源码按照您的部署流程弄的，为啥还会有这种问题，以下是安装gulp的文字提示：
C:\Users\Administrator\Desktop\es6>npm install gulp -g
C:\Users\Administrator\AppData\Roaming\npm\gulp -> C:\Users\Administrator\AppDat
a\Roaming\npm\node_modules\gulp\bin\gulp.js
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.4 (node_modules\gul
p\node_modules\fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@
1.2.4: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“win32”,“arch”:“x64”}
)

• gulp@4.0.0
  updated 1 package in 55.861s