ActiveRecord -> Active Record [ci skip]

This will decouple Action Cable from Rails.

[ci skip]

Since Action Cable is getting integrated into rails/rails, the Travis
badge for rails/actioncable is not needed anymore.

Also following the standard of every other README to have `--` rather
than `-` to separating the name of the library from its description.

[ci skip] Getting to ready to merge into rails/rails

Thanks to feedback from @ascrazy, @jeremy, and @javan

* Realign `end` statements with the opening `class` statement.
* Pad JavaScript objects with spaces to match Rails styleguide and for consistency with other examples.

Adding some examples to the README. Since ActionCable is an engine, it can be run in-app in the same way that websocket-rails can be (and I will admit to shamelessly stealing the implementation to websocket rails). Also adding examples of passing params to subscription and rebroadcasting received message.

closes #80

This includes small styling / grammar changes to the README

Update readme to remove js from example, copies structure from https://github.com/rails/actioncable-examples