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 = [
diff --git a/setup.py b/setup.py
index 16c2779..522b981 100644
--- a/setup.py
+++ b/setup.py
@@ -29,7 +29,7 @@
     "six>=1.9.0",
 )
 
-extras = {"aiohttp": "aiohttp >= 3.6.2, < 3.7.0dev; python_version>='3.6'"}
+extras = {"aiohttp": "aiohttp >= 3.6.2, < 4.0.0dev; python_version>='3.6'"}
 
 with io.open("README.rst", "r") as fh:
     long_description = fh.read()
diff --git a/system_tests/noxfile.py b/system_tests/noxfile.py
index 699a1b3..dcfe8ee 100644
--- a/system_tests/noxfile.py
+++ b/system_tests/noxfile.py
@@ -168,7 +168,7 @@
 
 # Test sesssions
 
-TEST_DEPENDENCIES_ASYNC = ["aiohttp < 3.7.0dev", "pytest-asyncio", "nest-asyncio"]
+TEST_DEPENDENCIES_ASYNC = ["aiohttp", "pytest-asyncio", "nest-asyncio"]
 TEST_DEPENDENCIES_SYNC = ["pytest", "requests"]
 PYTHON_VERSIONS_ASYNC = ["3.7"]
 PYTHON_VERSIONS_SYNC = ["2.7", "3.7"]