feat(django): Django4 support (#1632)

* Add Django 4 to test suite
* Manual test for async ORM queries and async class based views to show up in "Performance"

tox.ini

@@ -27,8 +27,8 @@ envlist =
     # Django 3.x
     {py3.6,py3.7,py3.8,py3.9}-django-{3.0,3.1}
     {py3.6,py3.7,py3.8,py3.9,py3.10}-django-{3.2}
-    # Django 4.x (comming soon)
-    #{py3.8,py3.9,py3.10}-django-{4.0,4.1}
+    # Django 4.x
+    {py3.8,py3.9,py3.10}-django-{4.0,4.1}
 
     {py2.7,py3.5,py3.6,py3.7,py3.8,py3.9}-flask-{0.11,0.12,1.0}
     {py2.7,py3.5,py3.6,py3.7,py3.8,py3.9,py3.10}-flask-1.1
@@ -115,6 +115,12 @@ deps =
     django-{2.2,3.0,3.1,3.2}: pytest-django>=4.0
     django-{2.2,3.0,3.1,3.2}: Werkzeug<2.0
 
+    django-{4.0,4.1}: djangorestframework
+    django-{4.0,4.1}: pytest-asyncio
+    django-{4.0,4.1}: psycopg2-binary
+    django-{4.0,4.1}: pytest-django
+    django-{4.0,4.1}: Werkzeug
+
     django-1.8: Django>=1.8,<1.9
     django-1.9: Django>=1.9,<1.10
     django-1.10: Django>=1.10,<1.11
@@ -125,6 +131,8 @@ deps =
     django-3.0: Django>=3.0,<3.1
     django-3.1: Django>=3.1,<3.2
     django-3.2: Django>=3.2,<3.3
+    django-4.0: Django>=4.0,<4.1
+    django-4.1: Django>=4.1,<4.2
 
     flask: flask-login
     flask-0.11: Flask>=0.11,<0.12