Bump jinja2 from 2.9.6 to 2.11.3

Bumps [jinja2](https://github.com/pallets/jinja) from 2.9.6 to 2.11.3.
- [Release notes](https://github.com/pallets/jinja/releases)
- [Changelog](https://github.com/pallets/jinja/blob/master/CHANGES.rst)
- [Commits](pallets/jinja@2.9.6...2.11.3)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements.txt

@@ -4,7 +4,7 @@ click==6.7
 Flask==1.0
 idna==2.5
 itsdangerous==0.24
-Jinja2==2.9.6
+Jinja2==2.11.3
 MarkupSafe==1.0
 pyzmq==16.0.2
 requests==2.20.0