Capture internal ale logger.

Change-Id: I316f52e31a0ce1a72a7119e154dfbf7b79987d62
Reviewed-on: http://review.couchbase.org/37742
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Reviewed-by: Artem Stemkovski <artem@couchbase.com>