Create a map of vehicle events.

[scrudden]

As per this comment, it is very useful to see vehicle events on a map.

https://github.com/TheTransitClock/transitime/blob/86c919096a32f53e2ac25b29a73c3b906d8fd9a8/transitclock/src/main/java/org/transitclock/db/structs/VehicleEvent.java#L47-L55

[scrudden]

Started doing this in a new project https://github.com/scrudden/RShinyTransitClock.