Elastic v5

[sberryman]

I'm going to attempt upgrading to elasticsearch v5.3. I'm going to try and use elastic's official registry at docker.elastic.co/elasticsearch/elasticsearch:5.3.0 for the base image. Anything you would like me to work on while making these changes?

• Elasticsearch 2.2 -> 5.3
• Containerpilot 2.1.0 -> 2.7.2
• Consul agent 0.7.5 (addition)

Do you still want to expose the volume?

[tgross]

Thanks for the contribution!

Anything you would like me to work on while making these changes?

Generally we like to keep the changesets of a size that makes it easier to review them. So doing the upgrades in one PR and any other work in a different PR would be best.

Do you still want to expose the volume?

Yes. It's essential for non-Triton environments.

[sberryman]

How would you suggest I break this PR up?