[Security] Bump werkzeug from 0.11.15 to 0.15.3

Bumps [werkzeug](https://github.com/pallets/werkzeug) from 0.11.15 to 0.15.3. **This update includes a security fix.**
- [Release notes](https://github.com/pallets/werkzeug/releases)
- [Changelog](https://github.com/pallets/werkzeug/blob/master/CHANGES.rst)
- [Commits](pallets/werkzeug@0.11.15...0.15.3)

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

Author: dependabot-preview[bot]

setup.py

@@ -35,7 +35,7 @@
             "Flask>=0.10",
             "python-dotenv>=0.7.1",
             "django-sslserver>=0.2",
-            "Werkzeug==0.11.15",
+            "Werkzeug==0.15.3",
         ],
         "dev": [
             "pre-commit==1.17.0",