Bump werkzeug from 0.15.4 to 0.16.0

Bumps [werkzeug](https://github.com/pallets/werkzeug) from 0.15.4 to 0.16.0.
- [Release notes](https://github.com/pallets/werkzeug/releases)
- [Changelog](https://github.com/pallets/werkzeug/blob/master/CHANGES.rst)
- [Commits](pallets/werkzeug@0.15.4...0.16.0)

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

Author: dependabot-preview[bot]

requirements.txt

@@ -4,4 +4,4 @@ itsdangerous==1.1.0
 Jinja2==2.10.1
 MarkupSafe==1.1.1
 virtualenv==16.7.8
-Werkzeug==0.15.4
+Werkzeug==0.16.0