fix ci

.github/workflows/CI.yaml

@@ -37,13 +37,13 @@ jobs:
 
       - uses: actions/setup-python@v4
         with:
-          python-version: '3.7'
+          python-version: '3.9'
           cache: 'pipenv'
 
       - name: Install pipenv
         run: |
           python -m pip install --upgrade pipenv wheel
-          python -m pipenv --python '3.7' install --dev
+          python -m pipenv --python '3.9' install --dev
 
       - name: Run flake8
         run: |
@@ -54,7 +54,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.7', '3.8', '3.9']
+        python-version: ['3.9']
     steps:
       - uses: actions/checkout@v3
 

Pipfile

@@ -9,9 +9,8 @@ nbconvert = ">=6.4.5"
 notebook = ">=6.4, <7.0.0"
 pyyaml = ">=3.13, <7"
 requests = ">=2.20.1"
-# nbconvert is not compatible with tornado 6 (which is in alpha)
-#tornado = ">=5"
 boto3 = ">=1.9"
+importlib-metadata = "<8.0.0"
 
 [dev-packages]
 flake8 = "*"