cmd，powershell，git-bash设置代理的方式是不一样的
    powershell
    $env:https_proxy = “127.0.0.1:1080”$env:http_proxy = “127.0.0.1:1080”
    git-bash
    export http_proxy=’127.0.0.1:1080’ export https_proxy=’127.0.0.1:1080’
    cmd
    set http_proxy=’127.0.0.1:1080’ set https_proxy=’127.0.0.1:1080’