Fixes to add python 3.6 compatibility

libp2p/tools/factories.py

@@ -1,5 +1,4 @@
 import asyncio
-from contextlib import asynccontextmanager
 from typing import Any, AsyncIterator, Dict, Tuple, cast
 
 import factory
@@ -33,6 +32,12 @@ from .constants import (
 )
 from .utils import connect, connect_swarm
 
+try:
+    from contextlib import asynccontextmanager
+except ImportError:
+    # NOTE: mypy complains about a duplicate import without the following ``# type: ignore``
+    from async_generator import asynccontextmanager  # type: ignore
+
 
 def initialize_peerstore_with_our_keypair(self_id: ID, key_pair: KeyPair) -> PeerStore:
     peer_store = PeerStore()