Merge pull request #38 from jupyterhub/ellisonbg-patch-1

Add better docs to the cull idle owner

host_vars/hostname.example

@@ -79,9 +79,10 @@ github_usernames: ['instructor', 'grader']
 
 # Optionally cull idle single user servers
 use_cull_idle_servers: false
-# The username and API token for culling idle servers
-# Create using something like `openssl rand -hex 32`
+# The username for culling idle servers. MUST be a user of JupyterHub,
+# so root won't work unless root can access JupyterHub
 cull_idle_servers_owner: instructor
+# The API token for culling, create using something like `openssl rand -hex 32`
 cull_idle_servers_hubapi_token: ''
 # The interval (in seconds) for checking for idle servers to cull
 cull_every: 600