Creo las excepciones de Viaje y Reserva

src/main/java/com/carpooling/carpoolingaoraha/excepciones/ReservaNoRegistrada.java

+package com.carpooling.carpoolingaoraha.excepciones;
+
+public class ReservaNoRegistrada extends RuntimeException{
+    public ReservaNoRegistrada(){}
+}

src/main/java/com/carpooling/carpoolingaoraha/excepciones/ViajeNoRegistrado.java

+package com.carpooling.carpoolingaoraha.excepciones;
+
+public class ViajeNoRegistrado extends RuntimeException{
+    public ViajeNoRegistrado(){}
+}