Firefox 47 with selenium marionette driver fails

[hugocorbucci]

Firefox 47 is only compatible with the marionette webdriver (https://developer.mozilla.org/en-US/docs/Mozilla/QA/Marionette/WebDriver).
Selenium needs to be configured to use such driver. Mainly it is:

1. Download the geckodriver from https://github.com/mozilla/geckodriver/releases. Extract it and rename it to wires. chmod +x wires. Put it on your path.
2. Change your Konacha configuration to be something like:

Konacha.configure do |config|
  Capybara.register_driver :selenium_marionette do |app|
    Capybara::Selenium::Driver.new(app, browser: :firefox, marionette: true)
  end
  config.driver = :selenium_marionette
end if defined?(Konacha)

1. Run

Upon running, however, even though the test, in the browser runs correctly, I now get, from the command line:
ERROR - Error communicating with browser process: TypeError: window.top.Konacha is undefined

Somehow, the context in which the session scripts execute is not the same as the ones where the JS files are loaded so a console.log(window.top.Konacha); in the runner.js and in the runner.rb yield different results. The former is correct. The latter is undefined.