MAR-148: Fixing linting errors:

- Do not compare against booleans when value is already boolean in
"when" conditions.
- Use pipefail in conjunction with setting the shell to Bash when
extracting the backup encryption key IDs.
- Do not compare variables to empty strings in "when" conditions. This
change currently works only for complex variables (stuff can break
badly in case of simple variables in current default Ansible
configuration).
- Fix missing space in one of Jinja2 templates.

MAR-135: Switch to using run_handlers instead of handlers as variable:

- Updated all roles to now depend on run_handlers being set to True in
order to force execution of handlers.

MAR-129: Updated LDAP client role and its tests for new Molecule and Ansible:

- Fixed linting issues.
- Moved test playbook variables into group_vars.
- Include linting configuration for tests from top-level directory.
- Updated how the target hosts are refenced in tests.
- Fixed Ansible warnings.

MAR-114: Updated task syntax for ldap roles:

- Updated ldap_client and ldap_server roles.
- Added and removed quoting where it makes sense.
- Switched to using expanded syntax (instead of one-liners).

MAR-25: Implemented tests for ldap_client role:

- Added Molecule configuration.
- Added test playbook.
- Fixed issue with mode not including leading zero.
- Implemented a couple of simple tests.