Integrate with discord permission nodes

[lekro]

• Require a particular rank/role/permission node to add matches/administrate
• Restrict bot's replies to certain channels
• This should be configurable
• Nicely ask for permissions to change user's roles if that's configured
• Think about configuration for roles (by name, by id?)

[chr1s-b]

This could be done with a function decorator around the commands. E.g

@commands.command
@role('Elo Manager')
def match(self,ctx):
    ...
    return

[lekro]

Implemented in 2c2ccfb7542216961f60629e8ffae6af76727de2. The permissions configuration is also in the configuration file.