Comment 0 for bug 1724896

There have been a number of microreleases of PHP 7.0 upstream since the
last update to Xenial (which corresponded to the last update in Zesty). As
it has been a few months, it feels appropriate to provide another
MRE update to php7.0. A number of critical security and bug-fixes are
present in each 7.0.x. Rather than backporting individual patches (e.g.,
Bug # 1569509), I believe it makes significantly more sense to follow
the upstream 7.0.x. Upstream PHP is demonstrating an improved approach
of bugfixes only in 7.0.x:

 - 7.0.24: http://php.net/ChangeLog-7.php

The upstream CI is at: https://travis-ci.org/php/php-src and is run
regularly.

Our php7.0 source package has autopkgtests for the 4 SAPIs, mod-php,
cgi, fpm and cli. We have also updated the packing to run the source
tests during the build itself.

I do not believe there is a firm statement from upstream on API/ABI
stability, but the general approach seems to be a BC-break would result
in 7.1.0 (which is present in Artful, and is why the Artful task is invalid).