Use latest release of Django 1.9

tox.ini

@@ -14,7 +14,7 @@ setenv =
 deps =
         django17: Django==1.7.11
         django18: Django==1.8.7
-        django19: https://www.djangoproject.com/download/1.9rc2/tarball/
+        django19: Django==1.9
         -rrequirements/requirements-testing.txt
         -rrequirements/requirements-optionals.txt
 
@@ -33,21 +33,21 @@ deps =
 # Specify explicitly to exclude Django Guardian against Django 1.9
 [testenv:py27-django19]
 deps =
-        https://www.djangoproject.com/download/1.9rc2/tarball/
+        Django==1.9
         -rrequirements/requirements-testing.txt
         markdown==2.5.2
         django-filter==0.10.0
 
 [testenv:py34-django19]
 deps =
-        https://www.djangoproject.com/download/1.9rc2/tarball/
+        Django==1.9
         -rrequirements/requirements-testing.txt
         markdown==2.5.2
         django-filter==0.10.0
 
 [testenv:py35-django19]
 deps =
-        https://www.djangoproject.com/download/1.9rc2/tarball/
+        Django==1.9
         -rrequirements/requirements-testing.txt
         markdown==2.5.2
         django-filter==0.10.0