这是我的代码：
require 'selenium-webdriver'
class TestSelenium
def initialize
driver = Selenium::WebDriver.for :firefox
driver.navigate.to "http://google.com"
end
end
这是我的错误消息：
/usr/local/rvm/gems/ruby-2.3.1/gems/selenium-webdriver-3.11.0/lib/selenium/webdriver/remote/http/common.rb:88:in `create_response': unexpected response, code=500, content-type="text/html" (Selenium::WebDriver::Error::WebDriverError)
from /usr/local/rvm/gems/ruby-2.3.1/gems/selenium-webdriver-3.11.0/lib/selenium/webdriver/remote/http/default.rb:104:in 'request'
from /usr/local/rvm/gems/ruby-2.3.1/gems/selenium-webdriver-3.11.0/lib/selenium/webdriver/remote/http/common.rb:59:in 'call'
from /usr/local/rvm/gems/ruby-2.3.1/gems/selenium-webdriver-3.11.0/lib/selenium/webdriver/remote/bridge.rb:164:in 'execute'
from /usr/local/rvm/gems/ruby-2.3.1/gems/selenium-webdriver-3.11.0/lib/selenium/webdriver/remote/bridge.rb:97:in 'create_session'
from /usr/local/rvm/gems/ruby-2.3.1/gems/selenium-webdriver-3.11.0/lib/selenium/webdriver/firefox/marionette/driver.rb:50:in 'initialize'
from /usr/local/rvm/gems/ruby-2.3.1/gems/selenium-webdriver-3.11.0/lib/selenium/webdriver/firefox/driver.rb:31:in 'new'
from /usr/local/rvm/gems/ruby-2.3.1/gems/selenium-webdriver-3.11.0/lib/selenium/webdriver/firefox/driver.rb:31:in 'new'
from /usr/local/rvm/gems/ruby-2.3.1/gems/selenium-webdriver-3.11.0/lib/selenium/webdriver/common/driver.rb:52:in 'for'
from /usr/local/rvm/gems/ruby-2.3.1/gems/selenium-webdriver-3.11.0/lib/selenium/webdriver.rb:85:in 'for'
from test_selenium.rb:6:in 'initialize'
from test_selenium.rb:11:in 'new'
from test_selenium.rb:11:in '<main>'