Print system logs (e.g. systemd), Riak errors, Solr logs, Ansible logs.

Prefer making Ansible to log to local file instead of [default
syslog](https://docs.ansible.com/ansible/intro_configuration.html#log-path)
in order not to spam syslog and to ensure printing out of all Ansible
logs (e.g. for identifying a "changed" task in the middle while
testing Ansible idempotency).

Taken from
https://github.com/antoiner77/caddy-ansible/blob/464794f4b8109e7e1ee67ec9af9fc2fef7323ed0/.travis.yml#L26-L32

... for idempotency.

This is a fix towards idempotency.

... for idempotency.

Closes #85

Test schema retrieved from [a yokozuna PR indexing RPT geospatial
fields](basho/yokozuna@5f21d38)
by running:
```
$ curl -f -o 'schema.xml.crdtgeospatialrpt' https://raw.githubusercontent.com/lucafavatella/yokozuna/5f21d38df63e066684b39ed9f83f6bde6c37ce42/priv/default_schema.xml
```

References:
* https://docs.basho.com/riak/kv/2.2.3/developing/api/http/store-search-schema/
* https://docs.basho.com/riak/kv/2.2.3/developing/api/http/store-search-index/
* #23 (comment)
* http://grokbase.com/t/gg/ansible-project/14cqkpbv1h/register-and-with-dict-with-items