Allow methods wrapped by EventFiringWebDriver and EventFiringWebElement to accept keyword arguments. - #806

@tbeadle can you descibe what was broken? and ideally add a scenario so it isn't broken in the future to the tests:

https://github.com/SeleniumHQ/selenium/blob/master/py/test/selenium/webdriver/common/correct_event_firing_tests.py

@lukeis This change is to make it so that, when an event listener is used, a caller can pass arguments by name and not just by position. I've added a unit test to demonstrate it. I confirmed that without my change, the test fails and with it, it passes. The Travis build failed for some reason, even though it shows that all the tests passed. I would appreciate any insight in to why that happened.

@tbeadle This seems like a nice useful fix. Can you please rebase your changes and also sign the CLA? If the CLA option doesn't appear, I think you should just create a new PR.

@tbeadle I've updated your first comment to put the CLA checkbox back in, can you confirm you've signed the CLA and check the box?

@lmtierney I've signed the CLA and updated the comment to select the checkbox.

thanks @tbeadle