Support different paths for elasticsearch-plugin

[phaedriel]

Pull Request (PR) description

• Add test path binary 'plugin'

Ref : https://discuss.elastic.co/t/missing-plugin-command-in-elastic/61995/2 > "elasticsearch-plugin is only applicable for 5.0 and above. if you are really on 2.4 then you need to use /usr/share/elasticsearch/bin/plugin."

This Pull Request (PR) fixes the following issues

Fixes #1172
Fixes #1109

[smortex]

Do you really want to fix/add support for ES < 5? As far as I can tell, anything older than 7.13.x is not supported:

https://www.elastic.co/fr/support/eol

Maybe we can just close the issue?

[phaedriel]

Do you really want to fix/add support for ES < 5? As far as I can tell, anything older than 7.13.x is not supported:

https://www.elastic.co/fr/support/eol

Maybe we can just close the issue?

• solution 1 : we add this small modification (i could add a comment to better explain in ruby code)
• solution 2 : i rollback and we suppress this indication "2.x" in readme (module description) "This module is actively tested against Elasticsearch 2.x, 5.x, and 6.x."

as you prefer ;)

[bastelfreak]

I think this is fine. This doesn't hardcode any paths with a version in it. It's possible that distros buil their own elasticsearch packages and use the old path.