add test for sending test TCP packet
add test for sending test TCP packet

cllamb0/dosenet-raspberrypi,bearing/dosenet-raspberrypi,yarocoder/dosenet-raspberrypi,bearing/dosenet-raspberrypi,tybtab/dosenet-raspberrypi,cllamb0/dosenet-raspberrypi,tybtab/dosenet-raspberrypi,yarocoder/dosenet-raspberrypi