3. Write a test for the ON DELETE CASCADE behavior.
-4. Add top-level message tables for all types so that we can link all
- records to a message and use the message's time stamp to (cascade)
- delete old data.
-
-5. Drop the many-to-many relation between at least odds and
- odds_games, since duplicate games are highly unlikely and the table
- will grow without bound.
+4. Add a test for inserting duplicate messages.