removing the redis container from postgres example

.github/workflows/postgres-service.yml

@@ -19,11 +19,6 @@ jobs:
         # needed because the postgres container does not provide a healthcheck
         options: --health-cmd pg_isready --health-interval 10s --health-timeout 5s --health-retries 5
 
-      redis:
-        image: redis
-        ports:
-        - 6379:6379
-
     steps:
     - uses: actions/checkout@v1     
     - run: npm ci