selenium中各種瀏覽器driver的放置位置
selenium2是自帶了很多瀏覽器的驅動，但是selenium3後需要自己下載了，所以配置selenium環境會有些亂。
首先，各個版本對應的瀏覽器版本（一定要對應，否則很可能出問題，或無法使用）
下載地址：
1.chrome_driver:http://chromedriver.storage.googleapis.com/index.html
2.firefox_geckodriver:https://github.com/mozilla/geckodriver/releases/
1.不同版本chrome下載位置：https://www.slimjet.com/chrome/google-chrome-old-version.php
2.不同版本firefox下載位置：http://ftp.mozilla.org/pub/firefox/releases/
ChromeDrive對應版本：
----------ChromeDriver v2.38 (2018-04-17)----------
Supports Chrome v65-67
----------ChromeDriver v2.37 (2018-03-16)----------
Supports Chrome v64-66
----------ChromeDriver v2.36 (2018-03-02)----------
Supports Chrome v63-65
----------ChromeDriver v2.35 (2017-10-03)----------
Supports Chrome v62-64
----------ChromeDriver v2.34 (2017-10-03)----------
Supports Chrome v61-63
----------ChromeDriver v2.33 (2017-10-03)----------
Supports Chrome v60-62
----------ChromeDriver v2.31 (2017-07-21)----------
Supports Chrome v59-61
----------ChromeDriver v2.31 (2017-07-21)----------
Supports Chrome v58-60
----------ChromeDriver v2.30 (2017-06-07)----------
Supports Chrome v58-60
----------ChromeDriver v2.29 (2017-04-04)----------
Supports Chrome v56-58
----------ChromeDriver v2.28 (2017-03-09)----------
Supports Chrome v55-57
----------ChromeDriver v2.27 (2016-12-23)----------
Supports Chrome v54-56
----------ChromeDriver v2.26 (2016-12-09)----------
Supports Chrome v53-55
----------ChromeDriver v2.25 (2016-10-25)----------
Supports Chrome v53-55
----------ChromeDriver v2.24 (2016-09-09)----------
Supports Chrome v52-54
----------ChromeDriver v2.23 (2016-08-04)----------
Supports Chrome v51-53
----------ChromeDriver v2.22 (2016-06-06)----------
Supports Chrome v49-52
----------ChromeDriver v2.21 (2016-01-28)----------
Supports Chrome v46-50
----------ChromeDriver v2.20 (2015-10-08)----------
Supports Chrome v43-48
----------ChromeDriver v2.19 (2015-08-28)----------
Supports Chrome v43-47
----------ChromeDriver v2.18 (2015-08-19)----------
Supports Chrome v43-46
火狐暫未查到比較全的，我是直接用的次最新driver加最新瀏覽器
存在位置：可以直接在python根目錄，或其Scripts資料夾中。