Add room version to room create request, persist in storage (#915)

* Add room version into createRoomReq

* Extract room version from m.room.create event when persisting

* Reduce cyclomatic complexity

* Update whitelist, gomatrixserverlib, tweaks to roomserver

* Update sytest-whitelist again

clientapi/jsonerror/jsonerror.go

@@ -124,6 +124,12 @@ func GuestAccessForbidden(msg string) *MatrixError {
 	return &MatrixError{"M_GUEST_ACCESS_FORBIDDEN", msg}
 }
 
+// UnsupportedRoomVersion is an error which is returned when the client
+// requests a room with a version that is unsupported.
+func UnsupportedRoomVersion(msg string) *MatrixError {
+	return &MatrixError{"M_UNSUPPORTED_ROOM_VERSION", msg}
+}
+
 // LimitExceededError is a rate-limiting error.
 type LimitExceededError struct {
 	MatrixError