We do not want users to hand-edit YAML files. This has been a
major source of bugs and confusion for users in z2jh. Doing so
in a terminal text editor makes it even worse.
This lets users type commands directly to modify config.yaml file
rather than edit files directly. This makes it a lot less error
prone and user friendly.
Advanced users can still edit config.yaml manually.
Fixes#38
- Load config only once at startup.
A lot of jupyterhub config (like user lists) take effect only at
startup, so live reload is not super useful. It will make the
software more complex, so let's not do it.
- Add pyyaml as a dependency of tljh.
- Remove escapism dependency since it is not actually used
