chore(controller): update psycopg2 to 2.6.1

See http://pythonhosted.org/psycopg2/news.html#what-s-new-in-psycopg-2-6-1

Author: mboersma

controller/requirements.txt

@@ -14,7 +14,7 @@ djangorestframework==3.0.5
 docker-py==1.1.0
 gunicorn==19.3.0
 paramiko==1.15.2
-psycopg2==2.6
+psycopg2==2.6.1
 python-etcd==0.3.2
 PyYAML==3.11
 setproctitle==1.1.8