安裝三大瀏覽器驅動driver
1.chromedriver 下載地址：https://code.google.com/p/chromedriver/downloads/list
2.Firefox的驅動geckodriver 下載地址：https://github.com/mozilla/geckodriver/releases/
3.IE的驅動IEdriver 下載地址：http://www.nuget.org/packages/Selenium.WebDriver.IEDriver/
火狐:http://ftp.mozilla.org/pub/firefox/releases/
selenium3.5
firefox 55.0
Firefox driver geckodriver-v0.19.0-win64.zip