Include external configuration files
Include external configuration files

In order to allow customizing some configuration without having to rebuild the image, we include all the configuration files in `/fluentd/etc/conf.d`

Partially solves #174
Provides a way to solve #181

Signed-off-by: Giuseppe Iannello <48aae147942ef7fb8e08815d7c506f513b4ababf@brokenloop.net>

fluent/fluentd-kubernetes-daemonset,fluent/fluentd-kubernetes-daemonset,fluent/fluentd-kubernetes-daemonset