Bump JupyterLab + friends

- Bumps JupyterLab to latest, lets us use prebuilt extensions
  finally
- Adds retrolab
- Bumps a couple other packages to latest, should hopefully have
  no real percievable differences

Requested by @ntaback in https://2i2c.freshdesk.com/a/tickets/57

environment.yml

@@ -30,22 +30,23 @@ dependencies:
 
   - pip:
     # Infrastructure things
-    - jupyterlab==2.*
-    - voila==0.2.3
-    - nbgitpuller==0.9.*
+    - jupyterlab==3.*
+    - retrolab==0.3.*
+    - voila==0.3.*
+    - nbgitpuller==1.0.*
     - jupyter-resource-usage==0.5.1
-    - jupytext==1.6.*
+    - jupytext==1.13.*
     - RISE==5.6.1
     - jupyter_contrib_nbextensions==0.5.1
     - jupyter-desktop-server==0.1.3
     - git-credential-helpers==0.2
     - notebook==6.1.6
-    - jupyterhub==1.3.0
-    - jupyter-server-proxy==3.1.0
+    - jupyterhub==1.5.0
+    - jupyter-server-proxy==3.2.0
     - jupyter-rsession-proxy==1.4
     - jupyter-shiny-proxy==1.1
     - jupyter-tree-download==1.0.1
-    - ipywidgets==7.6.2
+    - ipywidgets==7.6.5
     # This is temporary (ref: https://github.com/utoronto-2i2c/jupyterhub-deploy/issues/77)
     - jedi==0.17.2
 

install-jupyter-extensions.bash

@@ -1,12 +1,7 @@
 #!/bin/bash
 set -euo pipefail
 
-jupyter labextension install --debug \
-    @jupyter-widgets/jupyterlab-manager@2 \
-    @jupyterlab/[email protected] \
-    [email protected] \
-    [email protected] \
-    [email protected]
+jupyter labextension install --debug [email protected]
 
 # Install jupyter-contrib-nbextensions
 jupyter contrib nbextension install --sys-prefix