Fix aiohttp upgrade (#951)

* Revert "set max aiohttp version to 3.5.1 (until build is fixed) (#844)"

This reverts commit b2a4287.

* Fix test_run_with_aiohttp_not_installed

Somewhere between 3.5.1 and 3.5.2, the aiohttp reimport started
succeeding (in connexion.connexion.cli.run()). It's not clear which
change caused the issue, but it's probably one of:

- aio-libs/aiohttp#3469 (Remove wildcard imports)
- aio-libs/aiohttp#3464 (Don't suppress gunicorn cleanup errors)
- aio-libs/aiohttp#3471 (Refactor workers)
- aio-libs/aiohttp#3500 (Ignore done tasks)

In any case, setting sys.modules['aiohttp'] = None should prevent
reimporting it. See: https://stackoverflow.com/a/1350574

I successfully tested locally on py37 with aiohttp 3.5.1 and 3.5.2.

requirements-aiohttp.txt

@@ -1,4 +1,4 @@
-aiohttp>=2.2.5,<3.5.2
+aiohttp>=2.2.5
 aiohttp-swagger>=1.0.5
 ujson>=1.35
 aiohttp_jinja2==0.15.0

setup.py

@@ -35,7 +35,7 @@ def read_version(package):
 swagger_ui_require = 'swagger-ui-bundle>=0.0.2'
 flask_require = 'flask>=1.0.4'
 aiohttp_require = [
-    'aiohttp>=2.3.10,<3.5.2',
+    'aiohttp>=2.3.10',
     'aiohttp-jinja2>=0.14.0'
 ]
 ujson_require = 'ujson>=1.35'

tests/test_cli.py

@@ -262,6 +262,7 @@ def test_run_with_wsgi_containers(mock_app_run, spec_file):
 def test_run_with_aiohttp_not_installed(mock_app_run, spec_file):
     import sys
     aiohttp_bkp = sys.modules.pop('aiohttp', None)
+    sys.modules['aiohttp'] = None
 
     runner = CliRunner()