Finished data structure creation.
Fixed bug with multiple passengers on a flight.
Added some exception handling and started integrating with thymeleaf on flight confirmation page.
Merge branch 'oickle' into develop

Conflicts:
	.gitignore
	core/src/main/java/com/mycompany/pops/pojo/Passenger.java
	site/src/main/java/com/mycompany/controller/checkout/CheckoutController.java