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](https://github.com/pallets/werkzeug/compare/0.14.1...0.15.3)

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

requirements.txt

@@ -3,7 +3,7 @@ certifi==2018.4.16
 cffi==1.11.5
 chardet==3.0.4
 click==6.7
-cryptography==3.2
+cryptography==2.2.2
 Flask==1.0.2
 Flask-MySQL==1.4.0
 gunicorn==19.9.0
@@ -17,4 +17,4 @@ PyMySQL==0.9.2
 requests==2.19.1
 six==1.11.0
 urllib3==1.23
-Werkzeug==0.14.1
+Werkzeug==0.15.3