spec: test that multiple-recipient user notes actually work

Change-Id: Ie7aec4cd12177b8aa1ab39741acad2e09a84822c
Reviewed-on: https://gerrit.instructure.com/35697
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Drew Bowman <dbowman@instructure.com>
Product-Review: Braden Anderson <banderson@instructure.com>
QA-Review: Braden Anderson <banderson@instructure.com>