Bump ansible from 2.5.4 to 4.2.0

Bumps [ansible](https://github.com/ansible/ansible) from 2.5.4 to 4.2.0.
- [Release notes](https://github.com/ansible/ansible/releases)
- [Commits](https://github.com/ansible/ansible/commits)

---
updated-dependencies:
- dependency-name: ansible
  dependency-type: direct:production
...

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

Author: dependabot[bot]

requirements.txt

@@ -5,5 +5,5 @@ pyang==1.7.4
 requests==2.20.0
 urllib3==1.24.2
 xmltodict==0.11.0
-ansible==2.5.4
+ansible==4.2.0
 PrettyTable==0.7.2