on_connect and on_disconnect have no usage

[ejegouzo]

The 2 methods on_connect and on_disconnect defined in message_bus.rb are not called anywhere.

Why not calling these 2 methods in add_client and remove_client (lib/message_bus/connection_manager.rb) as in the following commit (made in a fork of the gem) : dexem@39fb7a1 ?

The use case to implement here is to log the start of a long polling connection and its end (using on_connect and on_disconnect) in order to count the number of long polling connections at any time.