Replace pusher with action cable (#178)

closes #43

spec/rails_helper.rb

@@ -4,6 +4,8 @@ require File.expand_path('../config/environment', __dir__)
 # Prevent database truncation if the environment is production
 abort('The Rails environment is running in production mode!') if Rails.env.production?
 require 'rspec/rails'
+require 'action_cable/testing/rspec'
+
 # Add additional requires below this line. Rails is not loaded until this point!
 
 # Requires supporting ruby files with custom matchers and macros, etc, in