Try postgresql service

.github/workflows/pythonpackage.yml

@@ -16,7 +16,21 @@ jobs:
     strategy:
       matrix:
         python-version: [3.7, 3.8]
-        TESTING_DB: [sqlite3, postgresql, mysql]   
+        TESTING_DB: [sqlite3, postgresql, mysql]  
+    services:
+      # Label used to access the service container
+      postgres:
+        # Docker Hub image
+        image: postgres
+        # Provide the password for postgres
+        env:
+          POSTGRES_PASSWORD: postgres
+        # Set health checks to wait until postgres has started
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5    
     steps:
     - uses: actions/checkout@v2    
     - name: Set up Python ${{ matrix.python-version }}