Major Patch

New features:
-When selecting your raid lineup the bot will now update the raid post in (almost) real time. Timeout on selecting your raid lineup has been increased from 20s to 60s.
-The bot command prefix can (and must) now be specified in the config file.
-The default class lineup for raid can (and must) now be specified in the config file.

Things will break if you do not update your config file, there is no fallback.
The example config file has been updated, so you can simply copy that and put your bot token in if you were using the default settings.

Bug fix:
-The background task now gets properly killed when you reload the code on a live bot so you do not end up with two copies running simultaneously.

Miscellaneous:
Some code optimization that you probably won't notice, unless it introduced new bugs. Hence releasing as a beta for now.