Add ability to connect to selenium hub from inside a proxy

[LeoVie]

Use case

I am using codeception behind a corporate proxy. My selenium grid is outside of the corporate network so I have to use the proxy server to connect to it.
In the suite config yml file you can specify http_proxy and http_proxy_port, but these are the settings that get injected into the browser itself to connect to the test object url. So we can't take use of them for this use case.

Solution

My suggested solution is to add two config keys to the suite config yml: webdriver_proxy and webdriver_proxy_port. These are passed to the facebook RemoteWebDriver which already supports this kind of proxy settings.

[Naktibalda]

Please make a pull request.

[LeoVie]

See Codeception/Codeception#5658 :)

[Naktibalda]

Codeception/Codeception#5658 created a new module rather than adding this feature to WebDriver.

Please raise a new pull request to https://github.com/Codeception/module-webdriver

[hgsgtk]

I want this feature too, so I'll propose it as a new feature of module-webdriver.

[hgsgtk]

@Naktibalda Hello, thanks for your great library to handle real browser via webdriver.
I sent a PR, would you check it, please?

#75