remove duplicate pipfile definitions also in setup.cfg, fix actions

.github/workflows/python-package.yml

@@ -25,9 +25,9 @@ jobs:
           python-version: ${{ matrix.python-version }}
       - name: Install dependencies
         run: |
-          python -m pip install --upgrade pip
-          python -m pip install flake8 pytest pipenv
-          pipenv install --system
+          python -m venv .venv
+          .venv/bin/python -m pip install --upgrade pip
+          .venv/bin/python -m pip install -e . flake8 pytest coverage
       # - name: Run pipenv check
       #   run: |
       #     # DDoS attacks in wheel and setuptools packages, not relevant
@@ -50,15 +50,15 @@ jobs:
       - name: Lint with flake8
         run: |
           # stop the build if there are Python syntax errors or undefined names
-          flake8 . --count --select=E9,F63,F7,F82 --ignore=F824 --show-source --statistics
+          .venv/bin/flake8 . --count --select=E9,F63,F7,F82 --ignore=F824 --show-source --statistics
           # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
-          flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+          .venv/bin/flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
       - name: Run tconnectsync --help
         run: |
-          tconnectsync --help
+          .venv/bin/tconnectsync --help
       - name: Test with pytest
         run: |
-          pytest
+          .venv/bin/pytest
       - name: Check codecov configuration
         run: |
           curl -X POST --data-binary @.codecov.yml https://codecov.io/validate
@@ -69,8 +69,7 @@ jobs:
           fi
       - name: Generate Coverage Report
         run: |
-          pip install coverage
-          coverage run -m unittest
+          .venv/bin/coverage run -m unittest
       - name: Upload Coverage to Codecov
         uses: codecov/codecov-action@v1
         with: