Drop Django 2.1 and below. (#7225)

Author: rpkilby

.travis.yml

@@ -5,20 +5,12 @@ matrix:
     fast_finish: true
     include:
 
-      - { python: "3.5", env: DJANGO=1.11 }
-      - { python: "3.5", env: DJANGO=2.0 }
-      - { python: "3.5", env: DJANGO=2.1 }
       - { python: "3.5", env: DJANGO=2.2 }
 
-      - { python: "3.6", env: DJANGO=1.11 }
-      - { python: "3.6", env: DJANGO=2.0 }
-      - { python: "3.6", env: DJANGO=2.1 }
       - { python: "3.6", env: DJANGO=2.2 }
       - { python: "3.6", env: DJANGO=3.0 }
       - { python: "3.6", env: DJANGO=master }
 
-      - { python: "3.7", env: DJANGO=2.0 }
-      - { python: "3.7", env: DJANGO=2.1 }
       - { python: "3.7", env: DJANGO=2.2 }
       - { python: "3.7", env: DJANGO=3.0 }
       - { python: "3.7", env: DJANGO=master }

README.md

@@ -55,7 +55,7 @@ There is a live example API for testing purposes, [available here][sandbox].
 # Requirements
 
 * Python (3.5, 3.6, 3.7, 3.8)
-* Django (1.11, 2.0, 2.1, 2.2, 3.0)
+* Django (2.2, 3.0)
 
 We **highly recommend** and only officially support the latest patch release of
 each Python and Django series.

setup.py

@@ -82,17 +82,15 @@ def get_version(package):
     author_email='tom@tomchristie.com',  # SEE NOTE BELOW (*)
     packages=find_packages(exclude=['tests*']),
     include_package_data=True,
-    install_requires=["django>=1.11"],
+    install_requires=["django>=2.2"],
     python_requires=">=3.5",
     zip_safe=False,
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Web Environment',
         'Framework :: Django',
-        'Framework :: Django :: 1.11',
-        'Framework :: Django :: 2.0',
-        'Framework :: Django :: 2.1',
         'Framework :: Django :: 2.2',
+        'Framework :: Django :: 3.0',
         'Intended Audience :: Developers',
         'License :: OSI Approved :: BSD License',
         'Operating System :: OS Independent',

tox.ini

@@ -1,18 +1,12 @@
 [tox]
 envlist =
-       {py35,py36}-django111,
-       {py35,py36,py37}-django20,
-       {py35,py36,py37}-django21
-       {py35,py36,py37}-django22
+       {py35,py36,py37}-django22,
        {py36,py37,py38}-django30,
        {py36,py37,py38}-djangomaster,
        base,dist,lint,docs,
 
 [travis:env]
 DJANGO =
-    1.11: django111
-    2.0: django20
-    2.1: django21
     2.2: django22
     3.0: django30
     master: djangomaster
@@ -24,9 +18,6 @@ setenv =
        PYTHONDONTWRITEBYTECODE=1
        PYTHONWARNINGS=once
 deps =
-        django111: Django>=1.11,<2.0
-        django20: Django>=2.0,<2.1
-        django21: Django>=2.1,<2.2
         django22: Django>=2.2,<3.0
         django30: Django>=3.0,<3.1
         djangomaster: https://github.com/django/django/archive/master.tar.gz