Add 'all good' job to be added as a required build

Author: hugovk

.github/workflows/test.yml

@@ -67,3 +67,6 @@ jobs:
       - name: Tox tests
         run: |
           tox -v -e ${{ matrix.tox-python-version }}-${{ matrix.tox-extra-versions }}-coverage55
+
+    allgood:
+        needs: [test]