Restore Python 3.7 support and update supported Python versions to include Python 3.9

Author: johnthagen

.circleci/config.yml

@@ -55,6 +55,12 @@ jobs:
       - image: circleci/python:3.8
         environment:
           TOXENV: docs
+  python37-drf310:
+    <<: *common
+    docker:
+      - image: circleci/python:3.7
+        environment:
+          TOXENV: 'py37-django{22,30}-drf310-tests'
   python38-drf310:
     <<: *common
     docker:
@@ -67,6 +73,12 @@ jobs:
       - image: circleci/python:3.9
         environment:
           TOXENV: 'py39-django{22,30}-drf310-tests'
+  python37-other:
+    <<: *common
+    docker:
+      - image: circleci/python:3.7
+        environment:
+          TOXENV: 'py37-django{22,30,31}-drf{311,312}-tests'
   python38-other:
     <<: *common
     docker:

docs/getting_started.rst

@@ -6,7 +6,7 @@ Getting started
 Requirements
 ------------
 
-* Python (3.8, 3.9)
+* Python (3.7, 3.8, 3.9)
 * Django (2.2, 3.0, 3.1)
 * Django REST Framework (3.10, 3.11, 3.12)
 

setup.py

@@ -71,9 +71,9 @@
         'Operating System :: OS Independent',
         'Programming Language :: Python',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
+        'Programming Language :: Python :: 3.9',
         'Topic :: Internet :: WWW/HTTP',
     ]
 )

tox.ini

@@ -1,7 +1,7 @@
 [tox]
 envlist=
-    py{38,39}-django{22,30}-drf310-tests
-    py{38,39}-django{22,30,31}-drf{311,312}-tests
+    py{37,38,39}-django{22,30}-drf310-tests
+    py{37,38,39}-django{22,30,31}-drf{311,312}-tests
     py39-djangomaster-drf312-tests
     lint
     docs