Upgrade Werkzeug to version 0.15.5.

requirements/dev.txt

@@ -5,9 +5,9 @@
 Sphinx==1.8.5 \
     --hash=sha256:9f3e17c64b34afc653d7c5ec95766e03043cc6d80b0de224f59b6b6e19d37c3c \
     --hash=sha256:c7658aab75c920288a8cf6f09f244c6cfdae30d82d803ac1634d9f223a80ca08
-Werkzeug==0.15.2 \
-    --hash=sha256:0a73e8bb2ff2feecfc5d56e6f458f5b99290ef34f565ffb2665801ff7de6af7a \
-    --hash=sha256:7fad9770a8778f9576693f0cc29c7dcc36964df916b83734f4431c0e612a7fbc
+Werkzeug==0.15.5 \
+    --hash=sha256:87ae4e5b5366da2347eb3116c0e6c681a0e939a33b2805e2c0cbd282664932c4 \
+    --hash=sha256:a13b74dd3c45f758d4ebdb224be8f1ab8ef58b3c0ffc1783a8c7d9f4f50227e6
 blessings==1.7 \
     --hash=sha256:caad5211e7ba5afe04367cdd4cfc68fa886e2e08f6f35e76b7387d2109ccea6e \
     --hash=sha256:b1fdd7e7a675295630f9ae71527a8ebc10bfefa236b3d6aa4932ee4462c17ba3 \