(potentially) implement Cat APIs

[benashford]

https://www.elastic.co/guide/en/elasticsearch/reference/current/cat.html

The utility of them is not obvious, however.

[polyfractal]

FWIW, the _cat APIs largely exist to be consumed on the cli by sysadmins. They give the same information as the various stats and info APIs, just in tabular format. That makes it easy to skim on the cli, and makes them awk/sed/grep/etc friendly. :)

[benashford]

Thanks @polyfractal, that makes sense. It seems unlikely a project like this would need to support them.