Updated User method parameters and added UserTests

[is1006]

• Updated User instance variables listofChatroom and friendsList from an Array of Strings to Array of Chatroom and User, respectively
• This is to be in line with the new updates of our code where we will reference the Users and Chatrooms this way instead of by their String usernames and chatroom displaynames
• Added new User Tests that test the different methods of User

[is1006]

Since we are not using loginTracker anymore, the instance variable loginTracker as well as the methods associated with it can be removed. So setLoginTracker, getLoginTracker and updateLoginTracker methods can be removed.

I removed the instance variable and all the methods associated with it in User. Also, edited the UserTests code as one of the arguments in expected results was incorrect.

[is1006]

Error: fatal: protocol error: bad pack header

Is this an error due to the repository having too many large files? It could also be due to the limited virtual memory. Not too sure how to fix this error