A sample project for testing compatibility

... between different versions of Selenium Java bindings and Selenium Grid

Start grid

./gradlew :grid2:run -- start Selenium Grid 2.53.1 on port 2222

./gradlew :grid3:run -- start Selenium Grid 3.141.59 on port 3333

./gradlew :grid4:run -- start Selenium Grid 4.1.2 on port 4444

Run tests

./gradlew :tests2:test -- runs tests on Selenium 2.53.1 (against all 3 grids)

./gradlew :tests3:test -- runs tests on Selenium 3.141.59 (against all 3 grids)

./gradlew :tests4:test -- runs tests on Selenium 4.1.2 (against all 3 grids)