Changed docker image for postgres in tests

.github/workflows/python-tests.yml

@@ -71,7 +71,7 @@ jobs:
       
     - name: Install pip dependencies
       run: |
-        python -m pip install --upgrade pip       
+        python -m pip install --upgrade pip setuptools
         pip install -r requirements-test.txt
         pip install -U django==${{ matrix.django-version }}.*
         python setup.py -q install