Notify slack on scheduled test failure (#427)

.github/workflows/test_and_deploy.yml

@@ -55,6 +55,17 @@ jobs:
           python-version: ${{ matrix.python-version }}
           secret-codecov-token: ${{ secrets.CODECOV_TOKEN }}
 
+
+      - name: Notify slack on scheduled failure
+        if: failure() && github.event_name == 'schedule'
+        uses: ravsamhq/notify-slack-action@v2
+        with:
+          status: ${{ job.status }} # required
+          notify_when: 'failure'
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_NOTIFYBOT_WEBHOOK_URL }} # required
+
+
   build_sdist_wheels:
     name: Build source distribution and wheel
     needs: [test]