Branch of 7.x and start testing against Elasticsearch 8.0

[ruflin]

The first releases of Elasticsearch 8.0 (alpha / beta) are shipping. Because of this, Elastica should branch off the 7.x branch and start testing against 8.0 on master. This will also allow us to do some necessary cleanup in the code base. This issue is to track these changes.

[deguif]

Let's tackle this, here's what I propose to do :

• create 7.x branch
• bump elasticsearch/elasticsearch to ^8.0 on master
• bump minimum PHP version to ^8.0 on master
• remove deprecated code

[ruflin]

Mostly sounds good to me. About the PHP version, 7.4 is still supported for about a year. Should we directly jump to 8? What do we gain / loose?

Can you directly take care of the branching and the ES change, I assume we have time for the PHP decision.

[thePanz]

I support @ruflin on the PHP side, 7.4 is still used a lot :)
Should we convert this issue into a "Conversation"? WDYT? (it's a new feature of GitHub)

[deguif]

Yes let's discuss this on a conversation ;)
There was this one already: #1961