User Authentication Interface

Just a simple user authentication interface, to mock this component
Simple User authentication interface, to help mock the method
Delete UserAuth
Updated Student.java

Moved it from parent folder, didn`t realise i put it in there instead of in the src folder, sorry
removed Student class
Updated User file

Updated User class to support the authentication method
Updated Main class

Updated Main class to support user authentication. It now requests
username and password until password is 6 chars long
Update User.java
resolved merge conflicts