npm端口已在使用中
$ lsof -i tcp:3000
$ kill -9 PID
如何关闭端口3000运行
### For Linux/Mac OS search (sudo) run this in the terminal:
$ lsof -i tcp:3000
$ kill -9 PID
### On Windows:
netstat -ano | findstr :3000
tskill typeyourPIDhere
### change tskill for taskkill in git bash