stop testing django 3.0 as its EOL (#8136)

Author: auvipy

tox.ini

@@ -1,7 +1,6 @@
 [tox]
 envlist =
        {py35,py36,py37}-django22,
-       {py36,py37,py38}-django30,
        {py36,py37,py38,py39}-django31,
        {py36,py37,py38,py39}-django32,
        {py38,py39}-djangomain,
@@ -10,7 +9,6 @@ envlist =
 [travis:env]
 DJANGO =
     2.2: django22
-    3.0: django30
     3.1: django31
     3.2: django32
     main: djangomain
@@ -23,9 +21,8 @@ setenv =
        PYTHONWARNINGS=once
 deps =
         django22: Django>=2.2,<3.0
-        django30: Django>=3.0,<3.1
         django31: Django>=3.1,<3.2
-        django32: Django>=3.2a1,<4.0
+        django32: Django>=3.2,<4.0
         djangomain: https://github.com/django/django/archive/main.tar.gz
         -rrequirements/requirements-testing.txt
         -rrequirements/requirements-optionals.txt