Selenium

* Fix bug when creating an Opera driver (5266)
* Stop sending sessionId in w3c payload. (4620)
* Fix issue with w3c actions releasing on element (5180)
* A more descriptive log message is displayed if the port cannot be connected (2913)
* Initialize Alert object by calling alert.text (1863)
* PhantomJS is now deprecated, please use either Chrome or Firefox in headless mode
* Legacy Firefox driver: ensuring copy of profile dir, its 'extensions' subdir and 'user.js' file are writable. (1466)

* Firefox options can now be imported from selenium.webdriver as FirefoxOptions (5120)
* Headless mode can now be set in Chrome Options using `set_headless`
* Headless mode can now be set in Firefox Options using `set_headless`
* Add the WebKitGTK WebDriver and options class (4635)
* Browser options can now be passed to remote WebDriver via the `options` parameter
* Browser option parameters are now standardized across drivers as `options`. `firefox_options`,
`chrome_options`, and `ie_options` are now deprecated
* Added missing W3C Error Codes (4556)
* Support has been removed for Python versions 2.6 and 3.3

* need to pass applicable environment variables to tox
* Fix active_element for w3c drivers (3979)
* add support for minimize command
* add support for fullscreen command
* window rect commands should fail on firefox and remote (legacy)
* Fix python backward compatibility for window commands (4937)
* Update docstrings to specify the type of path needed to install firefox addons. (4881)
* Update python chromeOptions key for capabilities (4622)
* Fix python pause action implementation (4795)

* Fix package name in python webelement module (4670)
* Fix python driver examples (3872)
* No need to multiply pause by 1000
* Add pause to action chains
* only check for proxyType once
* lowercase proxy type for w3c payload in python 4574
* guarding against null return value from find_elements in python 4555
* remove unnecessary pytest marking, address flake8 issues
* allow IE WebDriver to accept IE Options
* add IE Options class
* convert OSS capabilities to W3C equivalent for W3C payload
* Add Safari to API docs

* Numerous test fixes
*Iterate over capabilities in a way to support py2.7 and py3
* Fix W3C switching to window by name.
* Support GeckoDriver addon install/uninstall commands 4215.
* Move firefox_profile into moz:firefoxOptions.
* Filter non-W3C capability names out of alwaysMatch.
* Honor cmd line args passed to Service ctor (4167)
* Add expected conditions based on URL to Python Expected Conditions 4160
* Add network emulation to Chrome Python bindings (4011)
* add warning when saving incorrectly named screenshot (4141)

* Fix EventFiringWebdriver and WebElement to raise AttributeError on missing attributes. (4107)
* unwrap WebElements inside dicts