Upgrade JRE to version 8u121 and Elasticsearch to version 5.3.0.

Signed-off-by: Paulo Pires <[email protected]>

Upgrade base image to version 5.2.2_2.

Signed-off-by: Paulo Pires <[email protected]>

Hotfix

Did needed update (pires#36)

Upgrade Elasticsearch to version 5.2.1.

Upgraded Elasticsearch to version 5.2.0.

Use DISCOVERY_SERVICE env var (pires#29)

Upgraded Elasticsearch to version 5.1.2.

Removed bogus instruction in Dockerfile.

Upgraded Elasticsearch to version 5.1.1.

Fixes pires#23