Add errors file to be indexed by logstash
Add errors file to be indexed by logstash

In tripleo we grep for errors in logs and put them in one file.
This patch is for indexing only errors file in logstash server.

Change-Id: I95021ca826c75d7750bc2e56243ecc638bc1a502

openstack-infra/project-config,openstack-infra/project-config