Make it possible to switch the webdriver.xpi from the command line using a
system property.

Signed-off-by: Jason Leyba <jmleyba@gmail.com>
De-flaking PageLoadingTest. Tests are stable over 100 runs.

Signed-off-by: Jason Leyba <jmleyba@gmail.com>
@Ignore some ChromeDriver tests that fail with chromedriver 2.4

Signed-off-by: Jason Leyba <jmleyba@gmail.com>
General lint & test cleanup.

Signed-off-by: Jason Leyba <jmleyba@gmail.com>
Add a test for generating keyboard shortcuts with the interactions API

Signed-off-by: Jason Leyba <jmleyba@gmail.com>