added qemu dependency in travis ci for building img
added qemu dependency in travis ci for building img

Signed-off-by: Ronky <93acce8422a96ecba76315ed5fd1f6ff2b901235@gmail.com>

uavmarvin/How-to-Make-a-Computer-Operating-System,uavmarvin/How-to-Make-a-Computer-Operating-System,uavmarvin/How-to-Make-a-Computer-Operating-System