We should verify that schedule and audience users are active accounts,
and that we don't try to send report schedules either from/to them if
they aren't.
* Ordering issues from \core_reportbuilder\local\helpers\schedule's
get_schedule_report_users() method won't guarantee that the expected
task log output will always be the same as user two can be fetched first
before user one which will cause the message to be sent to user two
first. So just get the task log's output string and make sure it
contains the expected log strings.
Paul Holden