[mod] upgrade dependencies

Mostly interresting for :
* pyopenssl : https://github.com/pyca/pyopenssl/pull/578
* certifi

requirements.txt

@@ -1,10 +1,10 @@
-certifi==2017.1.23
-flask==0.12
-flask-babel==0.11.1
-lxml==3.7.3
+certifi==2017.7.27.1
+flask==0.12.2
+flask-babel==0.11.2
+lxml==3.8.0
 idna==2.5
 pygments==2.1.3
-pyopenssl==16.2.0
-python-dateutil==2.6.0
+pyopenssl==17.2.0
+python-dateutil==2.6.1
 pyyaml==3.12
-requests[socks]==2.13.0
+requests[socks]==2.14.2