add travis banner
add travis banner

alesiong/CUHKSZLib,cuhkshenzhen/CUHKSZLib,alesiong/CUHKSZLib,Yexiaoxing/CUHKSZLib,Yexiaoxing/CUHKSZLib,Yexiaoxing/CUHKSZLib,cuhkshenzhen/CUHKSZLib,cuhkshenzhen/CUHKSZLib,alesiong/CUHKSZLib