adding unique assignment to .eng role

[katag9k]

What

Adds breakingAllowMultiRoles to config, which if set to false will ensure that .point, .comms, triage and .eng can only be assigned to unique users.

Why

It gives the option to ensure people do not assign themselves to multiple roles and take on too much work during a breaking incident.

How

1. Set breakingAllowMultiRoles to false
2. Start a new breaking
3. Assign yourself to a role e.g. .comms
4. Assign yourself to a different role e.g. .point
5. The bot will not assign you to comms instead, it will let you know in a thread that you've already been assigned to a role

[katag9k]

Looking good! I'll try to give this a spin ASAP.

Did you get any feedback from others re: blocking on multi assignment vs swapping assignment?

Right now, without the unassign, there's no way to switch role. And even with unassign--if we do that--it'll be a two step process which could be one step.

Not yet, as it is still in discussion. But if we don't have the unassign feature, then swapping roles will have to be an option here.