Simplify docker build action for binder and update jlab (#252)

Author: jsignell

.github/workflows/ci-repo2docker.yaml

@@ -1,25 +1,12 @@
 name: repo2docker CI
-
 on: [push, pull_request]
 
 jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - name: Checkout
-        uses: actions/checkout@v2
-
-      - name: Set up Python 3.7
-        uses: actions/setup-python@v1
-        with:
-          python-version: 3.7
-
-      - name: Install repo2docker
-        run: |
-          python -m pip install --upgrade pip
-          # Explicitly adding `six` as a workaround for https://github.com/docker/docker-py/pull/2844
-          # Explicitly adding `chardet` as a workaround for https://github.com/jupyterhub/repo2docker/issues/1065
-          python -m pip install jupyter-repo2docker six chardet
-
-      - name: Build dask-tutorial Docker image
-        run: jupyter-repo2docker --no-run --debug .
+    - name: Build and cache on mybinder.org
+      uses: jupyterhub/repo2docker-action@master
+      with:
+        NO_PUSH: true
+        MYBINDERORG_TAG: ${{ github.event.ref }}

binder/environment.yml

@@ -3,7 +3,7 @@ channels:
   - conda-forge
 dependencies:
   - python=3.9
-  - jupyterlab=2
+  - jupyterlab=3
   - numpy=1.23
   - scipy=1.8
   - bokeh=2.4