Create DataManagement.java
Update DataManagement.java

Now properly registers customer. Must create RegisteredCustomers.csv file in project root folder. If the customer has already been registered, nothing happens.
Update DataManagement.java

Now works using the Command design pattern.
Create Command.java

Command interface for the commands.. Offers flexibility with allocation of commands left to run time.
Create RegisterCustomerCommand.java
Create Customer.java

Customer class that works with command design pattern
Update DataManagement.java

Now checks if a rental has already been stored, and if not, it can save it to Rentals.csv
Update DataManagement.java
Merge pull request #2 from Kidsan/Data

Data