Implement the Contact methods of the API

[malkam03]

The following methods must be implemented:

Method	Resource	Param	Body	Result
GET	https://url/contacts/	BranchID, ChapterID*	-	Contacts List(if no ChapterID is provided, return branch contacts)
PUT	https://url/contacts/	BranchID, ChapterID*	Contact	Status code
UPDATE	https://url/contacts/	BranchID, ChapterID*, ContactID	Contact(blank are left unmodified)	Status code
DELETE	https://url/contacts/	BranchID, ChapterID*, ContactID	-	Status code

* optional parameters.