Merge pull request #3765 from linovia/feature/fix_guardian_for_dj_19

Update the Django-guardian version for Django 1.9

requirements/requirements-optionals.txt

 # Optional packages which may be used with REST framework.
 markdown==2.5.2
-django-guardian==1.3.0
+django-guardian==1.3.2
 django-filter==0.10.0

tox.ini

@@ -30,24 +30,3 @@ deps =
        -rrequirements/requirements-testing.txt
        -rrequirements/requirements-documentation.txt
 
-# Specify explicitly to exclude Django Guardian against Django 1.9
-[testenv:py27-django19]
-deps =
-        Django==1.9
-        -rrequirements/requirements-testing.txt
-        markdown==2.5.2
-        django-filter==0.10.0
-
-[testenv:py34-django19]
-deps =
-        Django==1.9
-        -rrequirements/requirements-testing.txt
-        markdown==2.5.2
-        django-filter==0.10.0
-
-[testenv:py35-django19]
-deps =
-        Django==1.9
-        -rrequirements/requirements-testing.txt
-        markdown==2.5.2
-        django-filter==0.10.0