Unclear status of plugins for Shield and Watcher

The following plugins sources are nowhere to be found:
- logstash-output-elasticsearch-license
- logstash-output-elasticsearch-shield

But they are mentionned in the integration docs:
- https://www.elastic.co/guide/en/watcher/current/logstash-integration.html
- https://www.elastic.co/guide/en/shield/current/logstash.html

So it is difficult to help review them ;) in particular if they are up to date with LS2.x.

Also the elasticsearch-shield plugin seems in **contradiction to the switch to HTTP+SSL in the standard elasticsearch output done in LS2**
=> From LS2, the elasticsearch HTTP protocol should handle shield connection no?
=> elasticsearch-shield should in fact depend on elasticsearch-java no?

To finish it simply cannot be installed on top of LS2.1

```
# bin/plugin install logstash-output-elasticsearch-shield
Validating logstash-output-elasticsearch-shield
Installing logstash-output-elasticsearch-shield
Plugin version conflict, aborting
ERROR: Installation Aborted, message: Bundler could not find compatible versions for gem "logstash-output-elasticsearch":
In snapshot (Gemfile.lock):
logstash-output-elasticsearch (= 2.1.4)

In Gemfile:
logstash-output-elasticsearch-shield (>= 0) java depends on
logstash-output-elasticsearch (<= 0.1.9) java

logstash-output-elasticsearch (>= 0) java
```

So is this plugin still required ? for which LS versions ?
For sure the mentioned documentation must be updated with a separation between LS1.x and LS2.x
and maybe the gem must be yanked from rubygems: https://rubygems.org/gems/logstash-output-elasticsearch-shield or a dependency on logstash-core must be added for restriction