use requirements.txt for package install

make these versions explicit when package is installed for testing

Author: chrissimpkins

.github/workflows/py-ci.yml

@@ -41,6 +41,6 @@ jobs:
           update-setuptools: "true"
           update-wheel: "true"
       - name: Install project
-        run: pip install .
+        run: pip install -r requirements.txt .
       - name: Python unit tests
         run: pytest