issue #24: added phantomjs as possible webdriver
make sure that you've installed http://http://phantomjs.org and start tests with 
   grails -Dgeb.env=phantomjs test-app
or - if you are using windows - with
   grails "-Dgeb.env=phantomjs" test-app

Some of the tests will fail. It seems that this is because the test tries to set the object id through changing an <input type=hidden /> field. Phantomjs seems to not like this and throws an exception.