ci,tox,README: adjust to django branch master -> main

.github/workflows/main.yml

@@ -87,7 +87,7 @@ jobs:
           python: 3.8
           allow_failure: false
 
-        - name: py39-djmaster-sqlite-coverage
+        - name: py39-djmain-sqlite-coverage
           python: 3.9
           allow_failure: true
 

README.rst

@@ -28,7 +28,7 @@ pytest-django allows you to test your Django project/applications with the
   <https://pytest-django.readthedocs.io/en/latest/contributing.html>`_
 * Version compatibility:
 
-  * Django: 2.2, 3.0, 3.1 and latest master branch (compatible at the time of
+  * Django: 2.2, 3.0, 3.1 and latest main branch (compatible at the time of
     each release)
   * Python: CPython>=3.5 or PyPy 3
   * pytest: >=5.4

pytest_django/plugin.py

@@ -516,7 +516,7 @@ def _django_set_urlconf(request):
         def restore():
             django.conf.settings.ROOT_URLCONF = original_urlconf
             # Copy the pattern from
-            # https://github.com/django/django/blob/master/django/test/signals.py#L152
+            # https://github.com/django/django/blob/main/django/test/signals.py#L152
             clear_url_caches()
             set_urlconf(None)
 

tox.ini

@@ -10,7 +10,7 @@ envlist =
 [testenv]
 extras = testing
 deps =
-    djmaster: https://github.com/django/django/archive/master.tar.gz
+    djmain: https://github.com/django/django/archive/main.tar.gz
     dj32: Django>=3.2b1,<4.0
     dj31: Django>=3.1,<3.2
     dj30: Django>=3.0,<3.1