As an IM system it shall support channel based communication

[greenlaw110]

1. Description

Provides a RESTful API to create channel. Login user who joined the channel should be able to send message to channel, which will route the message to users in the channel

1.1 Implementation

Question:

1. should the message contains channel information?
2. what properties should a channel have

2. Acceptance criteria

1. create a communication channel
2. add two users (user a and user b) into the channel
3. user a send message the the channel

expected: both user a and user b received the message