Test

Add utest. #235

Job	Run time
multiple-arch-aarch64	5m 28s
cygwin64-cache	2m 58s
multiple-arch-armv7	5m 29s
utest-regression-blackbox-test	5m 11s
cygwin64	8m 5s
fast	1s
build-ubuntu20	1m 46s
build-centos7	2m 18s
build-cross-arm	2m 30s
build-cross-aarch64	2m 42s
build-ubuntu16	1m 33s
build-ubuntu18	1m 39s
coverage	3m 8s
multiple-arch-amd64	1m 19s
test-done	1s
	44m 8s

Provide feedback