Time to balance matchmaker: Make duo queues opt in.

Title says it all. Pretty tired of solo queuing, and getting stuck with a duo queue on my team. I don't have hard numbers, but I'm fairly confident the majority of duo queues I get are either toxic, bad, or throwing the matchmaking all out of whack with some low plat trying to boost his gold buddy.

I'll take longer queue times if it means not having to worry about getting a duo queue.