add cmocka tests

CMakeLists.txt

Dockerfile

cmake/modules/FindCMocka.cmake

entrypoint.sh

supervisord.conf

test/CMakeLists.txt

test/Makefile

test/files/input/wifi.ap.stations.failure.json

test/files/input/wifi.ap.stations.json

test/files/input/wifi.status.json

test/files/input/wifi.wps.status.failure.json

test/files/input/wifi.wps.status.json

test/files/output/wifi.start.json

test/files/output/wifi.status.failure.json

test/files/output/wifi.status.json

test/schema_test.c

test/test.c