fix: update delete_post endpoint to include db dependency and add initial tests for main route

test_papi.py

@@ -0,0 +1,12 @@
+#!/bin/env python3
+
+from fastapi.testclient import TestClient
+
+import papi
+client = TestClient(papi)
+
+
+def test_read_main():
+    response = client.get("/")
+    assert response.status_code == 200
+    assert response.json() == {"message": "Hello World"}