Implement the Users methods of the API

[malkam03]

The following methods must be implemented:

Method	Resource	Param	Body	Result
GET	https://url/users/	UserID*	-	User Info(if no UserID is provided, return all users info)
PUT	https://url/users/	-	User	Status code
UPDATE	https://url/users/	UserID	User(blank are left unmodified)	Status code
UPDATE	https://url/users/reminders	BranchID, ChapterID*, UserID, ActivityID	Boolean	Status code
UPDATE	https://url/users/notifications	BranchID, ChapterID*, UserID	User	Status code
DELETE	https://url/users/	UserID	-	Status code

* optional parameters.