composer.json settings allow dev versions for php: Specify max version

[Rebecca Blundell]

Looking at composer.json to see if we should update dependencies to make tests run better, I see that our syntax for php >=5.3.3 allows any version above that specified with default stability as dev. It explains how I ended up with php 7.2 after running make initcomposer...
I think our default stability should be stable and that we should think about specifying a maximum version.

Should we also change our settings to allow some other upgrades if there is a new stable non-breaking release, or just leave things pinned? If we change to "^version", it allows upgrades up to but not including the next major version, which seems reasonable??

[Robert Lyon (robertl-9)]

Tagged as snacked-sized as the code change may be small but the initial testing will probably be an effort

As it will involve checking what versions of PHP work fine with current Mahara and which don't

[Rebecca Blundell (rjb-dev)]

This was fixed in another patch: https://bugs.launchpad.net/mahara/+bug/1772792