fix(alerts): fix css for stop popup to prevent overflow issues

Author: landonreed

lib/gtfs/components/StopMarker.js

@@ -37,7 +37,13 @@ export default class StopMarker extends Component<Props> {
         <strong>
           NOTE: Stop is parent station to {stop.child_stops.length} stop(s):
         </strong>
-        <ul style={{paddingLeft: '15px'}}>
+        <ul style={{
+          paddingLeft: '15px',
+          // Ensure that list does not become too long for popup to display
+          // properly.
+          maxHeight: '100px',
+          overflowY: 'scroll'
+          }}>
           {stop.child_stops.map((s, i) =>
             <li key={i}>
               {s.stop_name} ({s.stop_code ? s.stop_code : s.stop_id})