我使用 Github 帐户用户名和秘密 ID 安装了 jupyterhub 服务器。但是当我运行 jupyterhub 服务（https://my system ip:8000）时，我的服务不可用。我安装了python3.6。如何解决这个问题呢？？
root@johnjesus-HCL-Desktop:~# jupyterhub
[W 2018-05-15 14:38:10.001 JupyterHub app:366] JupyterHub.proxy_cmd is deprecated in JupyterHub 0.8, use ConfigurableHTTPProxy.command
[I 2018-05-15 14:38:10.002 JupyterHub app:834] Loading cookie_secret from /home/johnjesus/jupyterhub_cookie_secret
[I 2018-05-15 14:38:10.077 JupyterHub app:1528] Hub API listening on http://127.0.0.1:8081/hub/
[W 2018-05-15 14:38:10.079 JupyterHub proxy:415]
Generating CONFIGPROXY_AUTH_TOKEN. Restarting the Hub will require restarting the proxy.
Set CONFIGPROXY_AUTH_TOKEN env or JupyterHub.proxy_auth_token config to avoid this message.
[I 2018-05-15 14:38:10.079 JupyterHub proxy:458] Starting proxy @ https://*:8000/ …