Need to add corruptors guild

[jfharden]

The corruptors are missing from the list of guilds. We should probably add them.

[jfharden]

Oh and maybe the bank too?

So the harts have asked for this a couple of times, so I thought I would have a look.

The guilds are stored in the DB, and there is a config variable which says how many guilds there are.

The key to my problem here is it means adding things to the database, I don't think we have an actual system for database migrations but we do have the validateDatabase function @PeteAUK added, do you think it's reasonable for me to add it as a second check in that validation and do the migration then. It's an easy change to detect (10 guilds instead of 11 or 12)?

If you're happy with this approach I will do a PR to add this, and perhaps remove NUM_GUILDS from the config and just read the number of rows in the guilds table