Bump werkzeug from 0.14.1 to 0.15.3 in /tests/base

Bumps [werkzeug](https://github.com/pallets/werkzeug) from 0.14.1 to 0.15.3.
- [Release notes](https://github.com/pallets/werkzeug/releases)
- [Changelog](https://github.com/pallets/werkzeug/blob/master/CHANGES.rst)
- [Commits](pallets/werkzeug@0.14.1...0.15.3)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

tests/base/requirements-w-hashes.txt

@@ -83,7 +83,7 @@ urllib3==1.24.2 \
     --hash=sha256:4c291ca23bbb55c76518905869ef34bdd5f0e46af7afe6861e8375643ffee1a0 \
     --hash=sha256:9a247273df709c4fedb38c711e44292304f73f39ab01beda9f6b9fc375669ac3 \
     # via botocore
-werkzeug==0.14.1 \
-    --hash=sha256:c3fd7a7d41976d9f44db327260e263132466836cef6f91512889ed60ad26557c \
-    --hash=sha256:d5da73735293558eb1651ee2fddc4d0dedcfa06538b8813a2e20011583c9e49b \
+werkzeug==0.15.3 \
+    --hash=sha256:97660b282aa7e29f94f3fe378e5c7162d7ab9d601a8dbb1cbb2ffc8f0e54607d \
+    --hash=sha256:cfd1281b1748288e59762c0e174d64d8bcb2b70e7c57bc4a1203c8825af24ac3 \
     # via flask