Test (Capybara): add no-sandbox option to headless chrome driver

Activating this option fix the 'DevToolsActivePort file doesn't exist'
error.

https://stackoverflow.com/questions/50642308/webdriverexception-unknown-error-devtoolsactiveport-file-doesnt-exist-while-t

spec/support/capybara.rb

@@ -9,6 +9,7 @@ end
 
 Capybara.register_driver :headless_chrome do |app|
   options = Selenium::WebDriver::Chrome::Options.new
+  options.add_argument('--no-sandbox') unless ENV['SANDBOX']
   options.add_argument('--headless') unless ENV['NO_HEADLESS']
   options.add_argument('--window-size=1440,900')