Ansible lint failing

Summary

New ansible lint in version >= 4.0.0 finds bug in install_base.yml file.

Relevant logs and/or screenshots

playbook: backup-restore.yml
206 Variables should have spaces before and after: {{ var_name }}
/builds/apl/teamwork/roles/docker/tasks/install_base.yml:4
    msg: "{{ ansible_distribution }} {{ ansible_distribution_release }} {{ansible_distribution_version }} is not supported"

Possible fixes

Add one space in line 4 in that file.