fix deprecated pytest async warning

- Cleanup pending async tasks
- fix deprecated warning about event_loop

app/tests/conftest.py

@@ -0,0 +1,20 @@
+import pytest_asyncio
+import asyncio
+
+
+@pytest_asyncio.fixture
+async def my_loop():
+    event_loop = asyncio.get_running_loop()
+    yield event_loop                     
+
+    # Collect all tasks and cancel those that are not 'done'.  
+    tasks = asyncio.all_tasks(event_loop)
+    tasks = [t for t in tasks if not t.done()]
+    for task in tasks:
+        task.cancel()
+
+    # Wait for all tasks to complete, ignoring any CancelledErrors                                  
+    try:
+        await asyncio.wait(tasks)
+    except asyncio.exceptions.CancelledError:
+        pass