Voltha Alarm Management using OpenNMS and Elasticsearch
- Added necessary configuration to run a self-contained instance of
  OpenNMS
- Elasticsearch/Logstash is responsible for the interception of voltha
  alarms and to forward to OpenNMS

Amendment:
- Cleaned up untouched opennms config files
- Added Dockerfile and scripts to override the default entrypoint script

Change-Id: Id611a330f7274d016281e734ade79d22bfc0356b
diff --git a/compose/elasticsearch/logstash/Dockerfile b/compose/elasticsearch/logstash/Dockerfile
new file mode 100644
index 0000000..ad7cb1c
--- /dev/null
+++ b/compose/elasticsearch/logstash/Dockerfile
@@ -0,0 +1,5 @@
+# Build from latest stable load
+FROM docker.elastic.co/logstash/logstash:5.2.2
+
+# Add logstash plugins 
+RUN logstash-plugin install logstash-output-opennms