Was assuming that Member::currentMember() is set,
which isn't the case unless you log in beforehand and start a PHP session.
Given we want the checks to run on their own without user interaction,
they need to work in isolation through a single HTTP call containing
the basic auth info.
In live or test environments, you need to be logged in as an admin to
access dev/check, but that's not appropriate if you wish to use that
page for a service that automatically checks the health of a site.
