Bump jinja2 from 2.11.1 to 2.11.3 in /tests

Bumps [jinja2](https://github.com/pallets/jinja) from 2.11.1 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@2.11.1...2.11.3)

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

Author: dependabot[bot]

tests/requirements.txt

@@ -9,7 +9,7 @@ chardet==3.0.4
 cryptography==2.8
 docutils==0.15.2
 idna==2.9
-Jinja2==2.11.1
+Jinja2==2.11.3
 jmespath==0.9.5
 MarkupSafe==1.1.1
 ntlm-auth==1.4.0