[Model] Fix ActiveRecord sorted collection

[inkstak]

This is a fix for #608.
It also introduces tests against ActiveRecord 5.0.

The fix about sorted records is cover by a test, but there are still 10 errors on other subjects when running tests with AR 5.
I'didn't run unit tests as they are already failing.

[nickrivadeneira]

@inkstak You'll need to sign the contributor agreement: https://www.elastic.co/contributor-agreement

Would love for this to be merged in.

[inkstak]

Done !

[sfcgeorge]

Confirm this fix works for me, without it result order is all over the place. Had to monkeypatch it in as Rails 5 has been out long enough.

[connorshea]

@nickrivadeneira any updates on this?

[nickrivadeneira]

@connorshea I'm not an elasticsearch member unfortunately, I was just making sure that instak signed the agreement so this could be merged in when the elasticsearch team looks at it. This repo seems to be dead though :( The person we need is @karmi

[inkstak]

I confirm I signed the agreement. The github check is not up to date.

[karmi]

@inkstak, you were correct, the check has indeed been out of sync -- it's corrected now.

@nickrivadeneira, it's not dead, I just have a hard time keeping up with all the gems across the two repos. I'll pull the patch and verify locally and merge.

[nickrivadeneira]

@karmi Makes sense. Thanks for looking into this one

[karmi]

Hi, I've merged the patch into master, many thanks for that, and apologies again for the delay. I'm not sure when I'll get to a release, but if you want a patch release with the change, I can do it anytime.

(So, one reason why processing PRs is not a simple "pull, run tests, rewrite commit message, push" is that I needed fix all this while doing the pull, so the tests are green and we can add more patches on top of the branch without fear...)

[inkstak]

Thanks 👍