Update to 1.12.4
Update to 1.12.4

Adds ability to choose selenium 3.0.0-beta4
groupon/Selenium-Grid-Extras,rgonalo/Selenium-Grid-Extras,groupon/Selenium-Grid-Extras,groupon/Selenium-Grid-Extras,groupon/Selenium-Grid-Extras,rgonalo/Selenium-Grid-Extras,rgonalo/Selenium-Grid-Extras,rgonalo/Selenium-Grid-Extras,groupon/Selenium-Grid-Extras,rgonalo/Selenium-Grid-Extras