v0.0.1

First version of GoIM.

Feature:

• based on websocket.
• support endpoint 2 endpoint instant messaging.
• support broadcast to all online users.
• support put message to offline queue when target user offline, also support load offline messages.
• services register into consul as micro service.
• use gRPC between micro services and use http api for called by users.
• add docs website GoIM Docs