fix siri structs from erroring on random un-needed keys

run

@@ -0,0 +1,6 @@
+#!/bin/sh
+
+./target/release/transit-board &
+npm run start &
+sleep 5s
+firefox --new-tab "localhost:3000"

src/siri_structs.rs

@@ -24,15 +24,15 @@ pub struct ServiceDelivery {
 #[serde(rename_all = "PascalCase")]
 pub struct StopMonitoringDelivery {
   pub monitored_stop_visit: Option<Vec<MonitoredStopVisit>>,
-  pub response_timestamp: String,
-  pub valid_until: String,
+  pub response_timestamp: Option<String>,
+  pub valid_until: Option<String>,
 }
 
 #[derive(Serialize, Deserialize)]
 #[serde(rename_all = "PascalCase")]
 pub struct MonitoredStopVisit {
   pub monitored_vehicle_journey: MonitoredVehicleJourney,
-  pub recorded_at_time: String,
+  pub recorded_at_time: Option<String>,
 }
 
 #[derive(Serialize, Deserialize)]
@@ -59,8 +59,8 @@ pub struct MonitoredVehicleJourney {
 #[derive(Serialize, Deserialize)]
 #[serde(rename_all = "PascalCase")]
 pub struct FramedVehicleJourneyRef {
-  pub data_frame_ref: String,
-  pub dated_vehicle_journey_ref: String,
+  pub data_frame_ref: Option<String>,
+  pub dated_vehicle_journey_ref: Option<String>,
 }
 
 #[derive(Serialize, Deserialize)]
@@ -105,8 +105,8 @@ pub struct Situations {
 #[derive(Serialize, Deserialize)]
 #[serde(rename_all = "PascalCase")]
 pub struct PtSituationElement {
-  pub publication_window: PublicationWindow,
-  pub severity: String,
+  pub publication_window: Option<PublicationWindow>,
+  pub severity: Option<String>,
   pub summary: Vec<String>,
   pub description: Vec<String>,
   pub situation_number: String,

src/subway_stop_handler.rs

@@ -51,6 +51,7 @@ impl SubwayStopHandler {
               })
               .time();
               let duration = ((arrival_time - current_time).max(0) / 60) as i32;
+              //println!("{}, {}, {}", arrival_time, current_time, arrival_time-current_time);
 
               // Route
               let route_id = trip_update