Bump jinja2 from 2.7.3 to 2.11.3 in /demo-bottle

Bumps [jinja2](https://github.com/pallets/jinja) from 2.7.3 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@2.7.3...2.11.3)

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

Author: dependabot[bot]

demo-bottle/requirements.txt

@@ -1,4 +1,4 @@
 bottle==0.12.19
 beaker==1.6.4
 paste==1.7.5.1
-jinja2==2.7.3
+jinja2==2.11.3