Pulp

We have many uses of bare variables throughout the roles, resulting in this deprecation warning.

 [DEPRECATION WARNING]: evaluating pulp_install_db as a bare variable, this
behaviour will go away and you might need to add |bool to the expression in the
 future. Also see CONDITIONAL_BARE_VARS configuration toggle.. This feature
will be removed in version 2.12. Deprecation warnings can be disabled by
setting deprecation_warnings=False in ansible.cfg.

AIUI, Ansible 2.12 will change the default value of CONDITIONAL_BARE_VARS to false. So we have 2 options:

1. Explicitly set CONDITIONAL_BARE_VARS to true
2. {{ moustache }} our variables (except in `when` statements?) or use `| bool` as suggested by the warning