Look into RTM implementation

It would be cool to have a nice interface to subscribe to workspace notification via the RTM api. I started a branch feature/rtm, which has a command for connecting to the RTM api and tailing for events in the workspace.

RTM documentation
https://api.slack.com/rtm

[netromdk]

This is very cool! Then it could optionally log these events to a file, service, or parser of some kind. Or perhaps we could make slacker listen for events and do actions, like a bot, but kept very simple.

[netromdk]

Try to handle SIGINT/^C to stop the command gracefully and perhaps while keeping REPL? I've made an example of the trace here.