fix(deps): Revert "fix: pin 'aoihttp < 3.7.0dev' (#634)" (#632) (#640)

This reverts commit 05f95246fab928fe2f445781117eeac8088497fb.

The compatibility bug was fixed in the aioresponses package version 0.7.1 - https://pypi.org/project/aioresponses/

Fixes #632 
diff --git a/noxfile.py b/noxfile.py
index 3888144..b92f493 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -30,12 +30,7 @@
     "grpcio",
 ]
 
-ASYNC_DEPENDENCIES = [
-    "pytest-asyncio",
-    "aiohttp < 3.7.0dev",
-    "aioresponses",
-    "asynctest",
-]
+ASYNC_DEPENDENCIES = ["pytest-asyncio", "aioresponses", "asynctest"]
 
 BLACK_VERSION = "black==19.3b0"
 BLACK_PATHS = [