* Gets build to use elasticsearch-extras
Also adds ci script for building repo on CI servers
To use this change you need to:
1. Clone elasticsearch: `git@github.com:elastic/elasticsearch.git`
2. create a directory at the same level as elasticsearch called `elasticsearch-extra`
3. Clone this repository into the `elasticsearch-extra` directory
4. Run `gradle build` from the `elasticsearch-extra/prelert-legacy` directory or run `gradle :prelert-legacy:build` from the `elasticsearch directory
* Adds USE_SSH option to ci script
* iter
Original commit: elastic/x-pack-elasticsearch@ea127dfef0
Colin Goodheart-Smithe