Switch Complement branch back to master

[anoadragon453]

As of #88 (and #92), we're currently using a custom branch of Complement (anoa/knock_room_v7) which changes the room version of knock rooms from the unstable identifier (xyz.amorgan.knock) to 7, as specified by MSC2998. However as room v7 hasn't made it into a released version of the spec yet, we can't merge that change into Complement master yet.

This issue is a reminder to switch back to the master branch of Complement once it's been updated to use 7 as well.