First, the apparent errors with >= 9 and 99 in the Marseys and
referrals code after the refactor are not actually bugs: they were
bug fixes mixed in with the refactor to fix an off-by-one.
Next, instead of failing silently on the `not user` branch in
badge_grant, we throw a ValueError. This retains the current
behavior where users get 500s to report while also enforcing the
assertion near the edge of the function.
Snakes
7e54f858d3