Bump Recommended PHP version to PHP 7

[jorbin]

Follow up to #33758

PHP 7 has been released for 4 months now and there have been no major issues with running WordPress on. Let's bump the recommended version of PHP to continue encouraging people to run the latest and greatest PHP.

Once we decide to do it, a meta ticket will need to be opened to update things on WordPress.org

[mikeschroder]

FWIW, this has my +1.

[ocean90]

Noting that Tests_External_HTTP_Basis is using ​https://secure.php.net/supported-versions.php which would fail in 8 months I think.

[knutsp]

I/we run PHP 7 on most of my (client) sites (60) and see no reason this should not be the recommended version from now on.

[blobaugh]

I like it! I have not run into any issues with PHP 7 in a few months. Was running a beta before that had issues that seem to be ironed out.

[pento]

On the Tests_External_HTTP_Basis test, that's only for when we must updated the recommended version, there's no problem with updating it earlier.

While Core hasn't had any PHP 7 problems, are there any plugins with issues? The recommended PHP version should probably take the entire ecosystem into account.

[rmccue]

+1, especially given that the PHP team tests PHP against WordPress itself during development. Our experience with migrating to PHP 7 has had ~0 breakage in plugins, apart from warnings on PHP 4-style constructors.

[jeremyfelt]

+1 and, FWIW, VVV's develop branch is now PHP 7.0. This should be part of the next stable release at the end of May.

[jdgrimes]

+1. I've migrated a couple of sites to PHP 7 without issues from core or plugins, although some plugins do give off some notices (W3TC).

[mensmaximus]

+1. No issues with 7.0 any more

[pento]

Replying to jdgrimes:

although some plugins do give off some notices (W3TC).

Given that we have until the end of the year before we have to bump it, there's no harm in holding off until major plugins are confirmed to work without notices or warnings. Until we can confirm that, I'm -1 on bumping the version for now.

This is remembering that we're talking about the recommended PHP version. The recommended version should be providing an ideal experience for folks, we shouldn't be bumping to a bigger number just because it's there.

Given the PHP 5.6 support timeline, we'll be bumping it by WordPress 4.8 at the latest, so it'd be nice to use those intervening months to ensure the UX for the wider WordPress ecosystem under PHP 7 is solid.

[ocean90]

I agree with @pento here.

We shouldn't recommend PHP 7 if one of our own plugins isn't ready yet: #36281.