build(deps): bump werkzeug from 0.14.1 to 0.15.3

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>

requirements.txt

@@ -6,4 +6,4 @@ python-dotenv==0.8.2
 simplejson==3.13.2
 sqlalchemy==1.2.6
 tornado==5.0.2
-werkzeug==0.14.1
+werkzeug==0.15.3

setup.py

@@ -54,7 +54,7 @@ def execfile(fname, globs, locs=None):
     packages=find_packages(exclude=['ez_setup', 'example', 'test']),
     include_package_data=True,
     install_requires=[
-        'Jinja2 (~= 2.9)', 'SQLAlchemy (>= 1.2, < 1.3)', 'Werkzeug (~= 0.14.1)', 'honcho (~= 1.0.1)',
+        'Jinja2 (~= 2.9)', 'SQLAlchemy (>= 1.2, < 1.3)', 'Werkzeug (>= 0.14.1,< 0.16.0)', 'honcho (~= 1.0.1)',
         'python-dotenv (~= 0.8.2)', 'simplejson (~= 3.13.2)', 'tornado (~= 5.0)'
     ],
     extras_require={