Merge #1213

1213: Bump werkzeug from 0.15.2 to 0.15.3 in /core/admin r=mergify[bot] a=dependabot[bot]

Bumps [werkzeug](https://github.com/pallets/werkzeug) from 0.15.2 to 0.15.3.
<details>
<summary>Release notes</summary>

*Sourced from [werkzeug's releases](https://github.com/pallets/werkzeug/releases).*

> ## 0.15.3
> * Blog: https://palletsprojects.com/blog/werkzeug-0-15-3-released/
> * Changes: https://werkzeug.palletsprojects.com/en/0.15.x/changes/#version-0-15-3
> 
</details>
<details>
<summary>Changelog</summary>

*Sourced from [werkzeug's changelog](https://github.com/pallets/werkzeug/blob/master/CHANGES.rst).*

> Version 0.15.3
> --------------
> 
> Released 2019-05-14
> 
> -   Properly handle multi-line header folding in development server in
>     Python 2.7. (:issue:`1080`)
> -   Restore the ``response`` argument to :exc:`~exceptions.Unauthorized`.
>     (:pr:`1527`)
> -   :exc:`~exceptions.Unauthorized` doesn't add the ``WWW-Authenticate``
>     header if ``www_authenticate`` is not given. (:issue:`1516`)
> -   The default URL converter correctly encodes bytes to string rather
>     than representing them with ``b''``. (:issue:`1502`)
> -   Fix the filename format string in
>     :class:`~middleware.profiler.ProfilerMiddleware` to correctly handle
>     float values. (:issue:`1511`)
> -   Update :class:`~middleware.lint.LintMiddleware` to work on Python 3.
>     (:issue:`1510`)
> -   The debugger detects cycles in chained exceptions and does not time
>     out in that case. (:issue:`1536`)
> -   When running the development server in Docker, the debugger security
>     pin is now unique per container.
</details>
<details>
<summary>Commits</summary>

- [`9b1123a`](9b1123a779) release version 0.15.3
- [`00bc43b`](00bc43b167) unique debugger pin in Docker containers
- [`2cbdf2b`](2cbdf2b022) Merge pull request [#1542](https://github-redirect.dependabot.com/pallets/werkzeug/issues/1542) from asottile/exceptions_arent_always_hashable
- [`0e669f6`](0e669f6be5) Fix unhashable exception types
- [`bdc17e4`](bdc17e4cd1) Merge pull request [#1540](https://github-redirect.dependabot.com/pallets/werkzeug/issues/1540) from pallets/break-tb-cycle
- [`44e38c2`](44e38c2985) break cycle in chained exceptions
- [`777500b`](777500b646) Merge pull request [#1518](https://github-redirect.dependabot.com/pallets/werkzeug/issues/1518) from NiklasMM/fix/1510_lint-middleware-python3-compa...
- [`e00c7c2`](e00c7c2ced) Make LintMiddleware Python 3 compatible and add tests
- [`d590cc7`](d590cc7cf2) Merge pull request [#1539](https://github-redirect.dependabot.com/pallets/werkzeug/issues/1539) from pallets/profiler-format
- [`0388fc9`](0388fc95e6) update filename_format for ProfilerMiddleware.
- Additional commits viewable in [compare view](https://github.com/pallets/werkzeug/compare/0.15.2...0.15.3)
</details>
<br />

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core/admin/requirements-prod.txt

@@ -45,6 +45,6 @@ tabulate==0.8.3
 tenacity==5.0.4
 validators==0.12.5
 visitor==0.1.3
-Werkzeug==0.15.2
+Werkzeug==0.15.3
 WTForms==2.2.1
 WTForms-Components==0.10.4