Update default GeckoDriver version to v0.27.0
Update default GeckoDriver version to v0.27.0

seleniumbase/SeleniumBase,mdmintz/SeleniumBase,seleniumbase/SeleniumBase,mdmintz/SeleniumBase,seleniumbase/SeleniumBase,mdmintz/SeleniumBase,mdmintz/SeleniumBase,seleniumbase/SeleniumBase