circle: bump versions

requirements/base.txt

 amqp==1.4.6
 amqp==1.4.6
 anyjson==0.3.3
 anyjson==0.3.3
-arrow==0.6.0
+arrow==0.7.0
 billiard==3.3.0.20
 billiard==3.3.0.20
 bpython==0.14.1
 bpython==0.14.1
 celery==3.1.18
 celery==3.1.18
-Django==1.8.2
+Django==1.8.12
 django-appconf==1.0.1
 django-appconf==1.0.1
 django-autocomplete-light==2.1.1
 django-autocomplete-light==2.1.1
 django-braces==1.8.0
 django-braces==1.8.0
-django-crispy-forms==1.4.0
+django-crispy-forms==1.6.0
 django-model-utils==2.2
 django-model-utils==2.2
 djangosaml2==0.13.0
 djangosaml2==0.13.0
 django-sizefield==0.7
 django-sizefield==0.7