[ARCHITECTURE] Implement a no-match list

[lauramosher]

My gut is saying there are two types of no-match lists we need to make:

1. A no-match "already friends" list. These are people who already know each other, and the benefits of getting to know team members would be lost on these pairs.
2. A match-only-if-necessary list. These are people who have been previously matched, and so we should try to not match them first.

Thoughts?

[danielma]

I think that makes sense.

The "already friends" list feels v2 to me and the previous matches feels more important.

Other matches I've considered are:

• These people work on a team together (this seems less necessary, because we might see value from people on the same team having personal conversations instead of just work)
• These people both work in the Carlsbad office (this seems like it makes sense on some level, but also takes away from the level playing field we're trying to create)

[TheBerg]

I think keeping this as generic as possible is probably the best. Hopefully we can open source this puppy. So I think keeping it to just the "already friends" feature is probably good enough to solve most problems. If I don't want to match with people on my team, I just put them on my already friends list.