Fixed Unit Tests

- Fixed Unit Tests in chattest.py that broke when Issue #16 was fixed

  The unit test functions call self.api.enqueue(cmd, reply=cmd) to simulate calling the Skype API.
  Since the ALTER CHAT commands strip the chat_id from the reply reply!=cmd and the actual expected
  reply needed to be specified in 16 of the test functions.
  
  e.g:
      self.api.enqueue('ALTER CHAT spam ACCEPTADD')
  changed to:
      self.api.enqueue('ALTER CHAT spam ACCEPTADD', 'ALTER CHAT ACCEPTADD')