Support for socket.io like websockets

[joamag]

Description

Creating a websocket like real-time communication is currently very hard under the Appier environment.
It should be possible to do this kind of integration for the Tasks abstractions of the appier_admin infra-structure.

This issue is related to hivesolutions/appier#25

Implemenation

This feature should take inspiration in other node based implementations like Socket.io.