chore(controller): update django-guardian to 1.2.5

See django-guardian/django-guardian@v1.2.4...v1.2.5

Author: mboersma

requirements.txt

@@ -7,7 +7,7 @@ Django==1.6.10
 # FIXME: switch to upstream pending merge of https://github.com/kmmbvnr/django-fsm/pull/59
 git+https://github.com/deis/django-fsm@propagate-false
 django-cors-headers==1.0.0
-django-guardian==1.2.4
+django-guardian==1.2.5
 django-json-field==0.5.7
 djangorestframework==2.4.4
 docker-py==0.6.0