ABCs should import from collections.abc on Py3.7+

CONTRIBUTORS.txt

@@ -87,6 +87,7 @@ Georges Dubus
 Greg Holt
 Gregory Haynes
 Günther Jena
+Gus Goulart
 Gustavo Carneiro
 Hu Bo
 Hugo Herter

aiohttp/web.py

@@ -3,7 +3,7 @@
 import socket
 import sys
 from argparse import ArgumentParser
-from collections import Iterable
+from collections.abc import Iterable
 from importlib import import_module
 
 from . import (helpers, web_app, web_exceptions, web_fileresponse,

aiohttp/web_app.py

@@ -1,7 +1,7 @@
 import asyncio
 import logging
 import warnings
-from collections import MutableMapping
+from collections.abc import MutableMapping
 from functools import partial
 from typing import (TYPE_CHECKING, Any, Awaitable, Callable, List, Mapping,
                     Optional, Sequence, Tuple, Union)

tests/test_web_request.py

@@ -1,5 +1,5 @@
 import socket
-from collections import MutableMapping
+from collections.abc import MutableMapping
 from unittest import mock
 
 import pytest