Fix `kickUser` to set `"leave"` membership
Fix `kickUser` to set `"leave"` membership

There is no such thing as a `"kick"` membership in the spec. The fact that Synapse aliases `"kick"` to `"leave"` is unspecced behaviour.
matrix-org/matrix-ios-sdk,matrix-org/matrix-ios-sdk,matrix-org/matrix-ios-sdk,matrix-org/matrix-ios-sdk,matrix-org/matrix-ios-sdk