Update tox dependencies

Author: mvantellingen

tox.ini

@@ -9,9 +9,9 @@ extras =
     py{35,36,37}: async
     py{35,36,37}: tornado
 deps =
-    py{35,36,37}: aioresponses==0.4.2
-    py{35,36,37}: aiohttp==3.2.1
-    py{35,36,37}: pytest-asyncio==0.5.0
+    py{35,36,37}: aioresponses==0.5.0
+    py{35,36,37}: aiohttp==3.4.4
+    py{35,36,37}: pytest-asyncio==0.9.0
 commands = coverage run --parallel -m pytest {posargs}