[test-buttons] add a test case for buttons with text and icons
[test-buttons] add a test case for buttons with text and icons

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