Bump werkzeug from 0.12.2 to 0.15.3

Bumps [werkzeug](https://github.com/pallets/werkzeug) from 0.12.2 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@0.12.2...0.15.3)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

setup.py

@@ -122,7 +122,7 @@
         "Jinja2==2.7.2",
         "MarkupSafe==0.23",
         "SQLAlchemy==1.2.19",
-        "Werkzeug==0.12.2",
+        "Werkzeug==0.15.3",
         "itsdangerous==0.24",
         "python-gnupg==0.3.7",
         "pytz==2016.10",