tests: add a test for the new icon-name and icon-size button properties
tests: add a test for the new icon-name and icon-size button properties

jonnylamb/mx,clutter-project/mx,pwithnall/mx,pwithnall/mx,jonnylamb/mx,pwithnall/mx,pwithnall/mx,clutter-project/mx,jonnylamb/mx,clutter-project/mx,jonnylamb/mx,clutter-project/mx