use pipenv

Author: robkooper

.github/workflows/ci.yaml

@@ -21,8 +21,9 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install flake8 pytest
-        if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+        pip install flake8 pytest pipenv
+        pipenv run pip freeze > requirements.txt
+        pip install -r requirements.txt
 
     - name: Lint with flake8
       run: |