Update pytz from 2016.10 to 2017.2

requirements/prod.txt

@@ -342,17 +342,12 @@ python-gflags==2.0 \
 python-memcached==1.53 \
     --hash=sha256:bcf71371d997bb46a3168a7b63aae66b56cccacc025af9310db4315681ef8868 # pyup: ==1.5.3
 # pytz is required by Babel, celery
-pytz==2016.10 \
-    --hash=sha256:7d94af5a3ee62616da36f4a5d0138bbfb1cd52d987a8274c45e0c78167837e17 \
-    --hash=sha256:a1ea35e87a63c7825846d5b5c81d23d668e8a102d3b1b465ce95afe1b3a2e065 \
-    --hash=sha256:dc221460e0264cb274fbb328936f509ba53d912669cb9ef6244e434c910be138 \
-    --hash=sha256:4c6f3e3f2e8bcd49bbb0f6031f77c3a99a54733ad330cb022d64cf406cf1bcb2 \
-    --hash=sha256:44daacdf5bb50c1fa3bc2b6c4c1f5afd78217e1478fe10585fc7ce5e383b6669 \
-    --hash=sha256:40c443019f389a93055d2c43a6a425aa10fd0047506e95747197a5a0423e58f8 \
-    --hash=sha256:c6fc91277aafa1031f9acddb701298549b96fa5ccc621f61425ca98d15f5935c \
-    --hash=sha256:7016b2c4fa075c564b81c37a252a5fccf60d8964aa31b7f5eae59aeb594ae02b \
-    --hash=sha256:9a43e20aa537cfad8fe7a1715165c91cb4a6935d40947f2d070e4c80f2dcd22b \
-    --hash=sha256:aafbf066975fe217ed49d7d197b26903d3b43e9ca2aa6ba0a211081f13c41917
+pytz==2017.2 \
+    --hash=sha256:43f52d4c6a0be301d53ebd867de05e2926c35728b3260157d274635a0a947f1c \
+    --hash=sha256:d1d6729c85acea5423671382868627129432fba9a89ecbb248d8d1c7a9f01c67 \
+    --hash=sha256:54a935085f7bf101f86b2aff75bd9672b435f51c3339db2ff616e66845f2b8f9 \
+    --hash=sha256:39504670abb5dae77f56f8eb63823937ce727d7cdd0088e6909e6dcac0f89043 \
+    --hash=sha256:ddc93b6d41cfb81266a27d23a79e13805d4a5521032b512643af8729041a81b4
 raven==6.0.0 \
     --hash=sha256:c9b521eaa4f253b5ed96051ab8f7c8e61fe901f9fc18ee6d9ac99726fbcb14fe \
     --hash=sha256:cee2d745c762230383fc89365770552c93c71205ee92c6e6bbbd85fe4dbb2803