To make up for this:
- Move the functions defined in `jupyter-connection.el` to `jupyter-base.el`
- Add a `session` field to the `jupyter-kernel-manager` and `jupyter-channel`
classes
- Add a `kernel-info` field to the `jupyter-repl-client`
- Add a `conn-info` field to a `jupyter-session`
- Add a `session` field to `jupyter-kernel-client`