Elasticsearch version warning no longer needed

[Paul Goins]

The README.md has this text: "Also note Graylog doesn't support all versions of elasticsearch see the documentation for more details." That links to the Graylog 2.2 docs which specify that it won't work with Elasticsearch 5.x.

And indeed, the current elasticsearch charm (elasticsearch/32) currently refers to an apt repo with "5.x" in its URL. So it sounds like graylog/23 and elasticsearch/32 shouldn't work together, except... The graylog snap now bundles Graylog 2.3, which works fine with Elasticsearch 5.x.

Since this charm depends on the snap, it sounds like this is no longer an issue, and we can remove this warning. Thoughts?

[Paul Goins (vultaire)]

Submitted a trivial patch for review: https://code.launchpad.net/~vultaire/graylog-charm/+git/graylog-charm/+merge/363145

[Haw Loeung (hloeung)]

LP let's you link MPs to bugs, which I've just done.

[Tom Haddon (mthaddon)]

Marking as fix released since I've just released cs:graylog-28