CHANGE: Minor improvements + updated api docs

Backend/models/booking.go

@@ -203,7 +203,7 @@ func checkLastBooking(b Booking) bool {
 		log.Println("Error checking last booking: ", err)
 		return false
 	}
-	if int16(check_in_out) == b.CheckInOut {
+	if int16(check_in_out)%2 == b.CheckInOut%2 {
 		return false
 	}
 	return true