Rbkit client should be able to connect and talk to the server over websockets

[emilsoman]

There is an extension to Rbkit which allows you to connect to Rbkit running in Rack based servers (Rails, Sinatra) over the port used for regular HTTP requests. This is needed if we want to profile apps running on heroku or other cloud instances where opening up 2 ports just for Rbkit is not feasible. A sample app is hosted here.

Rbkit client should be able to establish a websocket connection with the server and be able to send and receive data over it. This means we'll need to add a websocket client inside Rbkit-client and be able to accept the URL of the app to connect to it. Once we have the data on the websocket, unpacking etc will remain the same.